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Three Astros Sabermetric Things

Astros Sabermetrics: Revising FIP with Stat Cast; Cuban Free Agent Gurriel; Inside Edge Team Data

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John Rieger-USA TODAY Sports

"You can sum up the game of baseball in one word: ‘You never know.’ "

—Joaquin Andujar, former Astros and Cardinals pitcher

Sure, baseball will always have unknowns.  And that adds to the intrigue of the game.  But it's also intriguing when numbers can make some of the unknowns a little less unknown.  Enter sabermetrics.

This is the sabermetrics version of Three Astros Things.  Three brief things, but with a saber twist.


Over the years, my sabermetric articles frequently featured new and (hopefully) improved pitching metrics.  Because it is difficult to isolate the results controlled by the pitchers from the role played by hitters and defenders, analysts continue to revise and tweak run prevention metrics.  The objective is to understand how current pitching performance affects future performance.

A recent fangraphs article, "Stat Cast FIP: Estimate the HRs" by Andrew Perpetua, introduces a promising revision to Fielding Independent Pitching (FIP).  FIP measures pitching performance based on strike outs, walks, and home runs allowed.  SC-FIP is based on using stat cast to revise the number of HRs in the FIP formula.  Based on historic stat cast data results, the author uses the exit velocity and launch angle for each HR to estimate the probability that it would normally be a HR.  For each pitcher, the FIP is revised to reflect the difference between the actual number of HRs and the estimated number of HRs.  Generally, the difference between actual HRs and estimated HRs is due to the ballpark characteristics and atmospheric conditions.

The article has an excel sheet which can be downloaded.  Based on that data, the listing below shows the changes in Astros' pitchers' FIP based on using SC-FIP.  A negative value indicates that stat cast causes a decrease in FIP and vice versa for a positive value.  The excel sheet reflects data before last week, and therefore may not include the pitcher's most  recent performance.


Change in Change

Number HRs in FIP
Tony Sipp -1.4 -0.81
Pat Neshek -0.7 -0.44
Ken Giles -1 -0.42
Michael Feliz -0.7 -0.28
Mike Fiers -1.5 -0.24
Dallas Keuchel -1.5 -0.2
Doug Fister -0.2 -0.03
Scott Feldman 0.3 0.1
Lance McCullers 0.4 0.11
Luke Gregerson 0.3 0.12
Collin McHugh 1.2 0.19
Chris Devenski 1.1 0.29
Will Harris 1.1 0.44
Josh Fields 1.1 0.95

Tony Sipp has had some bad outings, but also has suffered bad luck with HRs leaving the yard that wouldn't normally be HRs.  To varying degrees, the same can be said of Pat Neshak and Ken Giles.  Both Mike Fiers and Dallas Keuchel have FIPs which are inflated by HRs which were not hit well enough to normally result in HRs.  And this provides some additional evidence that perhaps Keuchel hasn't pitched as badly as it seemed.  On the other side of the ledger, McHugh, Devenski, Harris, and Fields have experienced some luck with long flyball outs that would normally be HRs.

If the SC-FIP was widely available, it could complement x-FIP (expected FIP).  x-FIP normalizes the pitcher's HR/flyball rate, making it equal to league average.  This indicates the potential for future regression in a pitcher's HR rate.  Presumably the increase or decrease in estimated HRs provided by stat cast data might indicate a higher liklihood that the regression will occur.  For example, the change in FIP caused by SC-FIP explains all of the difference between Ken Giles' x-FIP and FIP.  This would seem like pretty strong evidence that Giles' FIP is likely to regress to the lower x-FIP.

The fangraphs article also shows an interesting Astros-related effect on the FIP leaderboard.   At the time, Chris Devenski was No. 10 in FIP on the major league leaderboard.  However, if the leaderboard is adjusted for SC-FIP, Lance McCullers replaces Devenski with the 10th lowest SC-FIP.  This is because Devenski has experienced some lucky outs on balls which are normally home runs, while McCullers' actual HR total is relatively unchanged by stat cast data.  Either way, the Astros have a young pitcher on the major league leaderboard.

Yulieski Gurriel

The Cuban free agent, 32 year old Yulieski Gurriel, worked out for the Astros, with GM Jeff Luhnow in attendance.  This development spurred some speculation by TCB commenters and even some requests that TCB devote an article to the subject.  Before we get too excited, remember that Gurriel also worked out for other teams, including the Dodgers and Mets.  But, still, this is an unusual development for the Astros.  Given his age and likely substantial cost, as well as Valbuena's recent hot hitting, Gurriel wouldn't normally profile as a likely target for the Astros. But the Astros' front office may know something about Gurriel that we don't.  And if the Astros are impressed enough to sign Gurriel, he could move over to 3d base and Valbuena could split time at 1st base.  In that scenario, Gurriel could cover 3d base next year until Bregman or Moran is ready to move up to the majors; at that point, Gurriel then could shift to LF.

And perhaps there is a sabermetric connection here.  Will Carroll wrote a Fan duel insider article on Gurriel which cites "many" scouts who believe Houston is a logical landing spot for Gurriel.  Gurriel would pair up with Correa to provide a strong left side of the infield and the Astros' front office "won't be too scared of the Cuban stats."   Carroll thinks that the uncertainty of trusting Cuban baseball stats will worry other clubs, but he contends that statistical translation techniques provide some confidence in the projections.  He points to the Davenport Translation of Gurriel's Cuban stats which show an average slash line of .295/.336/.480 with 20 HR/year.   Davenport's projection for 2016-2020 is lower, with a 50 percentile slash line of .272/.321/.431.

Carroll also quotes a National League scout who says, "He could walk into any club – any club – and on day one, he’s the starting third baseman... He’s immediately the best player on a lot of teams."  That's interesting; but what we don't know is whether the Astros' internal projections for Gurriel would back up that assessment.

Inside Edge: The Little Things

Inside Edge is a professional sports data analytics service which uses professional scouts to evaluate play by play data.  You may already have seen the Inside Edge article on The Little Things: Luck.  But it's worth talking about, because of the implications for the AL West and the Astros.  Inside Edge tabulates the total number of "lucky" and "unlucky" plays in the following categories: cheap hits, hard outs, bad walk calls, bad strike out calls, and other factors such as bad hops and losing the ball in the sun.  The Rangers come out ahead of every team in baseball with +44 net luck plays.  The Astros come out last in the majors with -68 net luck plays.  These luck scores are not based on inferential statistics.  They are based on the evaluations of Inside Edge scouts grading each play and identifying lucky and unlucky plays.

Now, before you say that the Rangers just play better than everybody else, consider that Inside Edge also quantifies boneheaded defensive giveaways, and the Rangers have more giveaway plays than the Astros (51 for the Rangers and 50 for the Astros).  I have read comments from Rangers' fans who credit their team's smart base running for supposed luck.  However, Inside Edge also quantifies base running giveaways, and the Rangers are among the top 10 worst teams in base running giveaways (-11.4).  All I can do is go back to Joaquin Andujar's quote.

I can't leave the topic of base running giveaways without noting that the Astros are the worst team in this category.  By the end of May, the baserunning mistakes had cost the team 16 runs, which is equivalent to almost 2 wins.  The Inside Edge data indicates that George Springer and Jose Altuve were the principal culprits.  However, their base running giveaways are surpassed by a familiar name--the Brewers' Jonathon Villar--who is tied for second most base running giveaways in the majors.