Everything You Need to Know About Chroma Key and Green Screen Footage

first_imgIn this guide, we’ll walk through everything you need to know about green screen backgrounds and achieving a perfect chroma key.The use of green screens has come a long way over the past few decades. Technology that was primarily reserved for Hollywood blockbusters and local news stations is now utilized by many of your favorite YouTubers. Here, we’ll guide you through the entire process of using green screen backgrounds from start to finish. We’ll talk lighting, cinematography, keying, and common mistakes.What Is Green Screen and Chroma Keying?Image via MarvelBefore we jump into how to use a green screen, let’s learn what a green screen actually does and familiarize ourselves with a few key terms.Green Screen: Technically, this term refers to the colored background you want to make transparent and remove from your shot. This is usually a single colored backdrop, which can be any color, but is usually bright green because it is the color furthest away from human skin tones. (Blue screens were frequently used in the early days with film, and might still be used in certain cases.) Sometimes the term is used as a fit-all for the entire process of keying (see below).Chroma Key: This popular term goes hand-in-hand with green screen. It’s the actual technique of layering, or compositing two images based on color hues. Every color has a chroma range, hence where the terminology comes from.Keying: This term is used to describe the process of removing the green screen background in post-production using video editing software. When the green screen background has been keyed, it will be fully transparent. Then you can fill in that transparent area with a different image or video. The goal is to get the cleanest key possible, meaning there are no digital artifacts left on your image where the green screen was originally.Spill: This often refers to the colored light that reflects back onto your subject from the green screen. When a green screen is brightly lit, the light can actually reflect that color back onto your subject. There are a number of steps you can take to prevent spill, which we’ll discuss below.Rules of the Modern Green ScreenThe principles we use for overcoming the challenges of green screen are based on those from years ago, before we had digital compositing and video editing software. As you can imagine, the tools have changed quite a bit with modern video advancements. Here, we’ve broken down the new rules for working with green screens.1. Start with the right green (or blue)Use a non-reflective green screen material and look for colors such as “chroma key green” and “digi green.” These colors are toned to be ideal for use with green screens. Alternatively, blue screens can also be used, especially for replicating night scenes. Learn more about the green vs. blue screen debate to figure out which color is right for your shoot.2. Separate your subject from the backgroundKeep your subject at least six feet away from the green screen. This helps minimize spill and unwanted shadows appearing on the green screen background.3. RAW is KingFilm with the highest bit-rate/least compressed codec you can. 10-bit color will be superior to 8-bit. ProRes 442 and 444 are always great options and RAW is even better if you have that ability.4. Expose the background properlyLight your foreground and your backdrop separately. It is also important to light your green screen backdrop evenly. Proper lighting exposure helps to avoid excess green lighting spill.5. Eliminate motion blurFilming with a faster shutter speed reduces motion blur and helps provide a cleaner key. You can always add secondary motion blur back in during post-production.6. Let the software do the workUtilize chroma keying specific software, like the Delta Keyer in DaVinci Resolve, to get the best key quickly.How to Shoot a Green Screen SceneImage via The Walt Disney CompanyIt is crucial to plan ahead and visualize your final scene when shooting with a green screen. Concept art and storyboards can help with this process. But your main goal is to determine what is real and what is not in your scene. This means you want to know what will physically be in the scene, and what will be added in later during post-production. If your scene is particularly complex, with layers of green screen, you’ll want to establish a clear guide to everything.In certain cases, you may need real props on set that your actors can reference. In behind-the-scenes shots you will often see tennis balls hanging on the green screen set. These provide the actors with visual reference points. Lighting is another huge consideration. Think about lighting your character in order to match the lighting of the environment they will populate. This will make a drastic difference when it comes to the final chroma key composite, and layering everything together.In this section, we’ll cover all the steps and considerations for completing a green screen shoot. Here’s what we’ll dive into:PlanningLightingClean Chroma KeyStep 1: Planning Your Green Screen ShootDetermining ScaleThis is the time to calculate the scale of your final scene and the best lenses for filming your actors. If you are planning on creating a wide-angle scene, it makes sense to film your subjects at the correct scale. This process primarily relies on knowing the field of view of the lens used to film the background element, which is often referred to as a background plate. It’s essential that you shoot both the foreground and background with the same focal length lens, or at least as close as you can guesstimate if you don’t know the lens used to film the background plate.Image via Mark Vargo, Do the Math: Planning Your Green Screen ShootOne thing worth noting is that the wider the background shot is, the larger the green screen will have to be in order to completely film your actors. Luckily, Mark Vargo walks us through this process in this article, which utilizes the lens field of view to calculate the final green screen size required for any shoot. The more notes you have from the original background shot (such as lens, time of day, etc.) the easier this process will be.As a rule of thumb, wider shots that capture your actor’s entire body and action shots that require lots of movement will need a full green screen that also covers the ground, and maybe even the side of the shot. If this is the case, make sure the screen has no edges so that you can key in easily. You’ll want to use a curved screen and drops without hard edges to the floor or to side walls.Prepping Actors and ObjectsYou’ll have to prep actors and props for use on green screen. Obviously, avoid green! Actors shouldn’t wear green or they’ll end up transparent in the key. You should also avoid shiny objects, as these can reflect the green and cause transparent spots. If reflective objects must be used, you will likely have to manually mask around those objects in post-production. This can be very time consuming, so plan ahead if that is ultimately required.Step 2: Lighting a Green ScreenImage via Warner Bros.There are three non-negotiable rules to lighting a green screen:The lighting must be evenThe lighting must be soft and diffuseThe green screen must be lit separately from the subjectWhen lighting your green screen background, the goal is to get the lighting as even as possible. This helps ensure that the green coloring is even, with no hot spots or shadows, which will help with the chroma key process in post-production. You will also need to light your actors and the green screen separately, preferably with the actors and the green screen background at least six feet apart. Remember to match the lighting on your actor to the scene in which they’ll appear once the green screen is composited.In this article on green screen lighting, you’ll find the key to even lighting is the same for achieving soft light in any other shooting scenario — use big, soft light sources. Hard light sources with no diffusion will create hot spots on the green screen background. To diffuse your lights, you can use on-light diffusion boxes or set up large silk frames. If you are on a budget, try using a white bed sheet mounted on a c-stand a few feet in front of your light.The placement of your lights also matters. If you are only using two lights to illuminate your background, place one light on each side of the green screen, a few feet back on a 45 degree angle. You can fine tune/adjust the angle of each light to make sure they’re not overlapping too much in the center. Make sure you are using the same lights on each side of the green screen for consistency. On bigger productions, you may need to use overhead lighting, additional lights, or more diffusion, but the basic principles outlined here will be the same.Step 3: Getting a Clean Chroma KeyImage via Warner Bros.As mentioned, chroma key refers to the technique of compositing two images (or video clips) together based on color hues. And in our case, we are using a green screen to replace what is behind our actors. You will often hear the term “clean chroma key” when editors are referring to green screen composting. A clean chroma key composite is the end goal.Preventing SpillA clean chroma key will leave the actors or subject with crisp, defined edges that look natural. But oftentimes, digital artifacts, jittery/jagged edges and color spill from the green screen can appear. Spill is one of the biggest offenders – it happens when the green screen reflects back on your subject, creating a green halo that’s hard to get rid of in post.This article on clean chroma keying has some great tips and tricks that will help your chroma key results, including how to prevent spill with thoughtful planning. One of the first is deciding if you should use a green screen or blue screen. On today’s digital cameras, green will likely give you the cleanest key. However, if your actor has blonde hair or green clothing, you’ll likely have better results with a blue screen as green can spill into light-colored hair.Using Motion BlurThe whole point of the green screen process is to achieve sharp edges, and motion blur can undo this. For that reason, it’s best to film green screen shots with a fast shutter speed to eliminate motion blur. This may almost appear as a stuttering movement on the actors. You can fix this by adding motion blur back onto your actors in post-production. You can use CC Force Motion Blur in After Effects or try the third-party plugin ReelSmart Motion Blur. Adding motion blur back on your composite will make a noticeable difference.Film with a Low ISOYou also want to make sure you film your green screen scene with a low ISO setting – we recommend the lowest ISO setting your camera has available. This is because higher ISO levels introduce noise artifacts and those will appear on the green screen background. This can result in a lot of “off-color” spots on the green screen background that can make the keying process more difficult.How to Key a Green Screen SceneIf you have followed the green screen workflow recommendations so far, keying your footage will be much easier. Always fix any issues on set if you notice them, because the old adage “fix it in post” won’t work well with green screen footage. It really is a multifaceted process that requires a coordinated workflow.Keying with Your NLE of ChoiceImage via Rubidium Wu, Working with a Green Screen Is Easier than Ever — Here’s WhyNowadays you have a lot of options when it comes to the chroma key software you can use for keying your green screen footage. Keying effects aren’t just limited to composing software anymore. Nearly every traditional non-linear editor has a chroma keyer built into it. There are even some great free software options available, such as HitFilm Express and DaVinci Resolve.Keying in DaVinci ResolveDaVinci Resolve is a free video editor that is regarded as one of the best color grading applications available. It also has some great chroma key tools as well. In this article learn how to pull a clean key in DaVinci Resolve from start to finish. Resolve’s effects are applied using a node-based workflow, which may take some time to get used to if you haven’t used one before. However, this node-based system will ultimately give you the most options when it comes to customizing your footage with various keying effects.Keying in After EffectsAdobe After Effects is another popular option (and this author’s chroma key software of choice). Because After Effects is a dedicated compositing program, you can imagine there are lots of effects you can use to refine your chroma key. The free built-in keyer effect called Keylight is quite powerful and was developed by The Foundry, the same company that makes Nuke, a powerful professional compositing application. Check out this tutorial to learn more about keying footage in After Effects.Keying in Premiere ProEven though Premiere Pro is first and foremost a non-linear editor, it has most of the powerful keying effects from After Effects built in it as well. In this in-depth article, Brent Pierce shows the entire chroma key process for Premiere Pro. The keying effects in Premiere Pro are fantastic if you need a quick turn-around on a project. They’ll save you from having to round-trip into After Effects, which will also save on render time/file management. The only drawback in Premiere Pro would be if you have to do a lot of manual masking. For that type of work, you will be much better off in After Effects.Keying in Final Cut Pro XFinal Cut Pro X has a more causal workflow when it comes to dealing with green screen footage. This can be useful for amateur video users or YouTubers who just need a quick solution. Add your green screen footage to your timeline, then apply the Keyer effect to the footage. It will automatically key out the green screen with varied results. You can continue to refine the look with some simple controls under the Video options when your clip is selected. Check out this tutorial for a simple walk through. Shutterstock also has some step-by-step instructions for keying your footage in Final Cut Pro X.Keying in HitFilm ExpressHitFilm Express is another free option and is comparable to After Effects, with a more compositing-focused workflow. You can key out your footage using two different effects, the Color Difference Key effect and the Hue & RGB Key effect. Check out this tutorial to see the chroma keyer workflow in HitFilm Express. Conversely, if you need an even more powerful keying option, they have a paid Chroma Keyer effect as well. (The Chroma Keyer effect is included in the paid version of HitFilm, but must be purchased separately if you are using the free HitFilm Express.)How to Fix Bad Green Screen FootageIf you are working with a less than ideal green screen setup, there are still methods you can take to help remedy the final footage. While there are some post-production options for fixing green screen mistakes, it’s always better to catch them on set.If your green screen background has problems…If your green screen background is less than ideal – for example, if the green screen has wrinkles on it – you can film with a shallow depth of field to help blur out the background. This will help smooth out wrinkles and potential shadows/hot spots, which will make the post-production keying easier.If there’s too much spill…Use masking as much as possible. As mentioned before, if your subject is wearing green clothing or reflective jewelry, you’ll probably want to manually create a mask around that area and key frame it. Then overlay that back on top of your footage, so it doesn’t get removed by accident during the keying process. I also recommend roughly masking out your actor prior to the key as well. Just make sure they don’t move outside of the masked area at any point. You can always set key frames for the mask and move it around if they do.Green screen spill can be tricky to get rid of. It often requires finding the perfect chroma key balance for the background and your subject, and then desaturating any green color remnants left on your subject.In this article from RocketStock, you can learn how easy it is to fine tune spill suppression with After Effects’ built-in tools. Getting this perfect will drastically help sell the final look of your chroma key.Cover image via TaraPattaDiscover more of our comprehensive guides to everything filmmaking:The Comprehensive Guide To Building Your Own Video Editing PCYour Guide to Getting Started Shooting RAW VideoDaVinci Resolve: THE Total Guide to the Best Free Video EditorChoosing Aspect Ratio: A Guide to Everything You Need to KnowThe Complete Video Editors Guide to Working with Musiclast_img read more

Naveen files nomination papers for Bijepur seat

first_imgOdisha Chief Minister and Biju Janata Dal president Naveen Patnaik filed his nomination papers for the Bijepur Assembly seat in Bargarh district of western Odisha on Monday.Mr. Patnaik, who is contesting the upcoming polls from two Assembly constituencies, had filed his nomination papers for the Hinjili seat in his home district Ganjam in south Odisha last week.Winning streakIt is for the first time since he assumed charge as Chief Minister in March 2000 that Mr. Patnaik is contesting the Assembly election from any part of western Odisha. He has been winning from Hinjili since he first contested in 2000 and thereafter in 2004, 2009, and 2014.According to political analysts, Mr. Patnaik is contesting the Assembly poll from western Odisha with a view to check the growth of the Congress and the BJP in the region, parts of which come under the backward Kalahandi-Balangir-Koraput region.Although the BJP finished third in the 2009 and 2014 Assembly polls in the State, the party has been trying hard to improve its tally since it emerged as the BJD’s main rival in the panchayat elections in 2017.Mr. Patnaik was accompanied with several party leaders, including sitting Bijepur MLA Rita Sahu, when he filed his nomination paper at the Sub-Collector’s office at Padmapur.In a tweet, Mr. Patnaik reminded the people of Bijepur of his words in the run-up to the bypoll held in the constituency early last year that the constituency’s development was his responsibility. The bypoll was held following the death of Ms. Sahu’s husband Subal Sahu who had won from Bijepur as a Congress candidate in 2014.Earlier in the day, Mr. Patnaik flagged off election campaign vans for the upcoming Assembly and Lok Sabha polls in Bhubaneswar before flying to Padmapur.As many as 350 LED vans will tour almost every village across the State disseminating information about the party’s achievements during its 19-year governance. The vans will also inform the people about the party’s policies and programmes.last_img read more

Dwight Howard fined $35,000 for obscene gesture in Cleveland

first_imgRead Next Trending Articles PLAY LIST 00:50Trending Articles00:50Trending Articles01:55Cops raid Manila office of Bayan, nab 3 activists for guns, explosive01:29Police teams find crossbows, bows in HK university01:35Panelo suggests discounted SEA Games tickets for students02:49Robredo: True leaders perform well despite having ‘uninspiring’ boss02:42PH underwater hockey team aims to make waves in SEA Games01:44Philippines marks anniversary of massacre with calls for justice01:19Fire erupts in Barangay Tatalon in Quezon City MOST READ Japan almost beats France, draw 23-23 in Paris Typhoon Kammuri accelerates, gains strength en route to PH Howard made the gesture in the second quarter of the Hornets’ 100-99 loss to the Cavaliers on Friday night. He was captured on video mimicking a sexual act.Howard is a 14-year veteran and eight-time All-Star. The 6-foot-11 center is averaging 15.5 points and 12.9 rebounds in 18 games this season.FEATURED STORIESSPORTSWATCH: Drones light up sky in final leg of SEA Games torch runSPORTSSEA Games: Philippines picks up 1st win in men’s water poloSPORTSMalditas save PH from shutout Stronger peso trims PH debt value to P7.9 trillion View comments LATEST STORIES CPP denies ‘Ka Diego’ arrest caused ‘mass panic’ among S. Tagalog NPA QC cops nab robbery gang leader, cohort Kris Aquino ‘pretty chill about becoming irrelevant’ Cleveland Cavaliers’ LeBron James (23) tries to break free of Charlotte Hornets’ Dwight Howard (12) during the first half of an NBA basketball game in Charlotte, N.C., Wednesday, Nov. 15, 2017. (AP Photo/Chuck Burton)NEW YORK — Dwight Howard of the Charlotte Hornets has been fined $35,000 for making an obscene gesture toward Cleveland fans.The NBA announced the fine on Saturday.ADVERTISEMENT Kammuri turning to super typhoon less likely but possible — Pagasa Brace for potentially devastating typhoon approaching PH – NDRRMC Don’t miss out on the latest news and information. Japan ex-PM Nakasone who boosted ties with US dies at 101last_img read more

ECB seeks clarification on Amir ban from ICC

first_imgEmbarrassed after banned Pakistani pacer Mohammad Amir played in one of its club matches, the England and Wales Cricket Board (ECB) has sought clarification from the ICC on the terms and conditions of the sanction imposed on him for involvement in spot-fixing.Banned Pakistani paceman Mohammad Aamer. APThe development comes after the ICC confirmed it was investigating reports that Aamer despite the five year ban on him for spot-fixing had played in a English division one match in Surrey league.The ICC ban on Amir — and his Pakistani teammates Salman Butt and Mohammad Asif — bars him from participating in the game at any recognised level and his turning up for the English club side could be in breach of the ICC terms and conditions on his sanction.The source said the ECB had told the PCB they were also investigating the matter but had also asked the ICC for clarification on the exact conditions of the sanction as Amir says he was told by the club organisers it would be alright for him to play in the match.When contacted, a senior official of the PCB said they were looking at the Amir issue but not taking it seriously.”As far as we are concerned the ICC bans specifically states that a banned player cannot play in any event or tournament that is organised, sanctioned or approved by the home board or its affiliated units,” the official said.”We also know that under the conditions of the sanction the player can also land into trouble if anyone connected with organising the match under review is connected in anyway to the home board or its affiliated units,” the official added.advertisementThe official said since the matter was concerning the ICC directly and Amir has been in London since last month, they were not following it up closely.”We are waiting to see what happens but if Amir has gone and violated the terms of his sanction unknowingly that is something we have to look at,” he said.Aamer on Wednesday told the ‘pakpassion.net’ website that he was innocent and didn’t know he was violating any term of his sanction as he was told by organisers that he was playing in a friendly fixture and not in any competition.Amir claimed four wickets and scored 60 runs playing for Addington in Surrey Cricket League Division One at the LSE ground in New Malden. “I was informed by club representatives before the game that it was a friendly match, being played on a privately owned cricket ground. I asked the club representatives if the match fell under the jurisdiction of ECB and they informed me that the match did not,” Amir told the website. – With PTI inputslast_img read more

10 months agoLiverpool boss Klopp: As soon as he wants, Mourinho can walk back into management

first_imgLiverpool boss Klopp: As soon as he wants, Mourinho can walk back into managementby Paul Vegas10 months agoSend to a friendShare the loveLiverpool boss Jurgen Klopp says sacked Manchester United boss Jose Mourinho can quickly jump back into management.Klopp says the 55-year-old losing his job is not as serious as it would be for a coach in the lower divisions.“I have to say, on our level – and it’s not that I don’t feel for him or whatever – if a manager got the sack in the Championship or in League One or League Two, that’s a bad moment, because you don’t know if they will get another job and stuff like that,” he said.“If Jose wants to have another job, he has it in two days. That’s really easy.”Klopp claims Mourinho is still “an outstanding manager”, because of everything he has achieved.“He has all my respect,” he said. “He was unbelievably successful.“Nobody can take away from him all the things he won and I wish he has that in his mind when he leaves and not a few other things, which happened in the last few months.” TagsTransfersAbout the authorPaul VegasShare the loveHave your saylast_img read more

10 months agoSolskjaer: A happy Pogba is good for Man Utd

first_imgSolskjaer: A happy Pogba is good for Man Utdby Paul Vegas10 months agoSend to a friendShare the loveManchester United boss Ole Gunnar Solskjaer says Paul Pogba is finding his best form because he’s in a happier mood.Pogba scored twice for victory over Huddersfield on Wednesday.”That’s the Paul I know, the one I’ve known since I had him in the reserves,” Solskjaer said. “He’s always been a happy boy and always had a big smile on his face.”When you play for United you should be happy. Of course it’s a responsibility but it’s also an honour and a privilege. He’s a United boy through and through.”He knows what it means to play for Man United. Paul created two or three last time, this time he scored two himself and I hope he’ll enjoy it.” About the authorPaul VegasShare the loveHave your saylast_img read more

25 days agoWilson insists Bournemouth only at 60 per cent

first_imgAbout the authorFreddie TaylorShare the loveHave your say Wilson insists Bournemouth only at 60 per centby Freddie Taylor25 days agoSend to a friendShare the loveBournemouth striker Callum Wilson says there is so much more to come from his side this season.The Cherries are seventh in the league, only a point off a top four position.Wilson has managed to score in the last four league games he has played. But the England international insists the team is still reaching its full potential.Wilson said to reporters: “I think we are only playing at 60 per cent.”We have a lot more to come individually and collectively. We will be working hard on that to make sure we improve over the coming weeks.”There’s key players missing but also, the ones who are playing – including myself – we’ve still got a lot more to give.”We are nowhere near where we can be performing at our best, but we are getting results at the moment which is a positive sign.”To go three unbeaten is good. It would have been good to get three wins on the bounce on Saturday. It’s definitely a missed opportunity.” last_img read more

Iowa Lands 4-Star CB Chevin Calloway

first_imgChilvin Calloway committing to Iowa.chevin calloway iowaChevin Calloway, a four-star cornerback recruit from Dallas, Texas, has announced his decision to play for the Iowa Hawkeyes in 2017. Calloway’s announcement was supposed to come this past Friday, but given the tragedy involving the Dallas police department, he chose to push it a few days. Calloway announced the news live on Periscope.Calloway is a 5-foot-10, 180-pound player who is ranked as the 15th-best athlete in the state of Texas. Here’s a screenshot of him wearing an Iowa hat after the announcement.pic.twitter.com/x4kekz2vOM— Chevin Calloway (@_chev1_) July 11, 2016Boom – Chevin Calloway #Hawkeyes pic.twitter.com/2fH6Zk04xZ— Hawkeye Images (@webcentrick) July 11, 2016Calloway, according to 247 Sports, had offers from nearly every major program – including Alabama, Notre Dame, Ohio State, Oklahoma and more.last_img read more

A Baseballs Exit Velocity Is Five Parts Hitter One Part Pitcher

For years sabermetrics has theorized that pitchers can’t control what happens after a batter strikes a ball. Whether it bloops in for a hit, rockets its way to an outfielder’s glove or lands just inches outside the foul line, it’s a consequence of the batter and the defense, but not the pitcher. That argument is what led to Fielding Independent Pitching (FIP), a statistic that attempts to quantify a pitcher’s performance only for the events for which we know the pitcher has definite responsibility (walks, strikeouts and home runs — in sabermetrics parlance, the “Three True Outcomes”). FIP throws out base hits completely on the basis that they are partially a product of the defense.But now we have Statcast. The new technology that collects data on the position and velocity of the ball and the players on the field is beginning to change what we know (or thought we knew) about all sorts of things — pitching included. And that’s raising new questions about how much effect a pitcher can have on a ball once it’s put in play. The answer might be: a lot.But first, let’s talk batters. Last week, I used Statcast to show that harder-struck pitches tend to fall for hits more often. That, generally, makes hard contact good for the hitter and bad for the pitcher. Obviously, some hitters are better at hitting the ball hard. What Statcast tells us is that some pitchers are better at making batters hit the ball softly.That’s not to say pitchers hold the upper hand. In my models1Specifically, I used a linear random effects model with the R package lme4. The model was specified as follows:Batted ball velocity ~ (1|hitter) + (1|pitcher) + (1|ballpark).In total, batter explains 3 percent of the variance in batted ball velocity, while pitcher explains 0.6 percent and park 0.03 percent. of batted ball velocity that incorporate the pitcher, batter and ballpark, the batter’s effect dominates the pitcher’s. A ball’s exit velocity after a bat strikes it is about five times more the batter’s doing than the pitcher’s. This fact seems to partially vindicate FIP — batters really are the ones in control.At the same time, the pitcher’s effect is not negligible.2Deriving a p-value in a random effects model is tricky. However, the random effect for pitchers significantly improves the model by AIC, improves out-of-sample prediction accuracy, and is larger than expected under a null distribution derived from permutations. While the best batters increase batted ball velocity by as much as 7-8 mph, the best pitchers suppress it by 1.5 mph compared with the average pitcher.That has real significance: Such a decrease roughly equates to a 13-point decrease in batting average on balls in play (BABIP) for a given batted ball.3This number comes from a logistic regression of exit velocity for each batted ball. Over the course of a game, the pitchers who can best decrease exit velocity save about a quarter of a run (on average). A quarter of a run doesn’t sound like much? Multiplied over a season, all those quarters of a run add up to about one win of value.4Run expectancy numbers are derived from a linear regression of linear weights value per pitch on batted ball velocity. Linear weights values come from Pitch Info.So that means FIP is flawed as an overall value metric, at least for some pitchers. Who are those pitchers? Here’s a table of all 485 pitchers with batted ball data this season as of the writing of this article.5This amounts to 17,768 batted balls. You may notice that most relievers are close to zero on this list. That’s because the model does not have enough data per reliever to be certain that they are altering velocity heavily, so it regresses their readings to the mean. Search for your favorite pitcher and see how many miles per hour he takes away from or adds to the average batted ball. The five best pitchers in the league: the Baltimore Orioles’ Wei-Yin Chen (balls leave the bat 1.63 mph slower than average when Chen pitches); the Chicago White Sox’s Chris Sale (1.56 mph); the Los Angeles Angels’ Garrett Richards (1.53 mph); the St. Louis Cardinals’ Adam Wainwright (1.46 mph, before he experienced a season-ending injury April 25); and the Houston Astros’ Dallas Keuchel (1.40 mph). Many of these pitchers are bona fide aces, most obviously Sale, Richards and Wainwright (Clayton Kershaw also lurks in ninth place). These players are not only adept at managing contact, they are also skilled strikeout artists. FIP accurately tabs them as great pitchers even without information about their contact-controlling abilities.These pitchers control their opposition’s quality of contact partly by driving the hitters into bad counts. In pitcher’s counts, hitters tend to put weak, defensive swings on the ball, resulting in glancing contact. About 15 percent of pitchers’ exit velocity suppression comes from controlling the count.6This estimate is derived by incorporating count into the model as a fixed effect and then determining how much the pitcher’s estimated random effect decreased. Richards, for example, has reached two-strike counts in 92 of his opponents’ plate appearances, compared with three-ball counts in only 38; in the former, hitters have a .271 BABIP, whereas in the latter, they have a .333 BABIP.7The league difference is a bit smaller, but still significant: .291 BABIP with three balls, .281 with two strikes.Chen is an intriguing case. The best at suppressing batted ball velocity, Chen also has the largest gap between ERA and FIP among qualified starters. In fact, Chen has put up a sizable gap between his ERA and FIP in three of the four years in which he’s pitched in MLB. Lacking batted ball velocity in years prior, we cannot say that his skill is consistent, but his results appear to be.FIP doesn’t only fail to credit the pitchers who manage their opponent’s batted ball velocity, it also fails to blame bad ones who consistently get hit hard.The league’s bottom five in that respect: the Pittsburgh Pirates’ Vance Worley (1.43 mph added to a ball’s exit velocity, compared with average); the Tampa Bay Rays’ Nate Karns (1.39 mph); the San Francisco Giants’ Tim Lincecum (1.16 mph); the Kansas City Royals’ Yordano Ventura (1.11 mph); and the San Diego Padres’ James Shields (1.06 mph). Just as the best pitchers tended to be better than average even by FIP, these five are worse. And while the aces use the count to their advantage, these pitchers are liable to find themselves in hitter’s counts, which causes some of their problems in the first place.Their exit velocity stats are also worse because they serve up pitches down the middle of the plate. Batters crave these meatballs and can punish them for extra-base hits and home runs. When I took pitch location out of the model, the pitchers’ effects on batted ball velocities fell by 20 percent on average.8Location was added into the model with a quadratic term for horizontal and vertical coordinates after adjusting for the count.Ventura, the Royals’ young flamethrower, is a conspicuous member of this worst-in-the-league list. Like Worley and Karns, he tends to throw his four-seam fastball more often than the league average.9Using pitch tags generously supplied to me by Pitch Info. That’s significant because fastballs tend to get hammered the hardest (even adjusting for count and location). Ventura, and other fastball-heavy starters, run the risk of allowing harder contact and more hits.The idea that pitchers can, in fact, influence their BABIP is not new. Shortly after the initial publication of DIPS, Tom Tippett (currently employed by the Red Sox) wrote about how the best pitchers seemed to be able to control the probability that their struck pitches would fall for hits. Tippett had only anecdotal examples such as Pedro Martinez and Greg Maddux, so the sabermetric community coalesced on the idea that they could be exceptions to a very reasonable rule.Now that we have Statcast’s data, we can see otherwise. No one will mistake Wei-Yin Chen for Pedro Martinez, but it appears that Chen can repeatably depress his opponent’s batted ball velocity, and a statistic such as FIP will fail to credit him for that skill.10Fortunately, new statistics such as Baseball Prospectus’ DRA (Deserved Run Average) do take into account all the events in which a pitcher plays a part. In fact, individual pitchers’ DRAs better correlate with the velocity suppression effects I calculated than their FIPs do, indicating that DRA is capturing some of this skill. Statcast’s data is beginning to challenge not only our views of specific players, but also some of the fundamental precepts of sabermetrics.Special thanks to Baseball Savant for the batted ball data; Pitch Info and Harry Pavlidis for the use of pitch tag data; and Jonathan Judge, Greg Matthews, Harry Pavlidis and Dan Turkenkopf for helpful comments and feedback.CORRECTION (May 22, 11:38 a.m.): An earlier version of this article stated that Wei-Yin Chen had a sizable gap between his ERA and FIP all four years in which he pitched in the league. That wasn’t true in 2013, when his ERA was slightly higher than his FIP. read more

Pellegrini rubbishes leak concerns

first_imgWest Ham manager Manuel Pellegrini has dismissed reports that he was concerned about his starting line ups getting leaked in advance.According to reports on Friday, Pellegrini was vexed by a Twitter account that has correctly predicted West Ham starting line ups for months.“First of all, it is not true – it is a lie. I am not angry about that.” Pellegrini told Sky Sports.“Not aware (of it) because normally, in every team I manage before, the day before the game I work with set-pieces.“So, all the players know the day before – who will play, who will not play.“So many players can talk with other players. I am not keeping the starting 11 until three or four hours before the game.Report: Rice is committed to West Ham not a United moveReport: Rice is committed to West Ham not a United move George Patchias – September 4, 2019 Declan Rice is committed to his West Ham contract and not a move to Manchester United.In an interview reported by football.london, Rice opens up…“There are a lot of reasons why some people can know the team.”Asked if he knew who was responsible for the tweets, Pellegrini added: “I don’t have any idea.“I am not worried about that, I am only worried about trying to win three points.“If you play against Chelsea, against Watford, against Liverpool, you are sure it will be the same starting XI (from those teams).“I don’t hide too much about the starting XI.”last_img read more