Bernstein: Age, Defense Suppress Cubs' Projection

The PECOTA algorithms project the Cubs to go 82-80 in 2019.

Dan Bernstein
February 07, 2019 - 3:06 pm
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(670 The Score) The wonks at Baseball Prospectus understand that you don't understand, and they have learned to have fun with it.

The PECOTA projection system is just algorithms, coldly and dispassionately processing terabytes of data to estimate the value of every player expressed in runs created and runs prevented, adding up the totals for teams based on expected playing time, translating the runs to wins and losses and then spitting out the standings.

Their site actually has an annual article entitled "Why PECOTA Hates Your Favorite Team" that accompanies the release, providing a detailed explanation of why and how some of the totals have ended up being what they are and transparently comparing previous projections with actual results.

A mere 82 wins for the 2019 Cubs is a big topic this year, and Rob Mains delved into what he called this years "exemplar of PECOTA hatred." He notes the Cubs had the National League's oldest pitching staff last year.

The rotation looks like Jon Lester (in his age-35 season), Jose Quintana (30), Cole Hamels (35), Kyle Hendricks (29), and Yu Darvish (32). The closer will be … Brandon Morrow (34)? Pedro Strop (34)? Steve Cishek (32)? Brach (33)? PECOTA, fully cognizant of aging curves, is projecting these old hurlers surrendering 730 runs in 2019 compared to 645 in 2018, over half a run more per game. It sees the team scoring 739 runs, less than a tenth of a run fewer per game. The pessimism is based on those aging pitchers.

​And there's more in the details as well, in how those runs get surrendered. PECOTA has been tweaked to include catchers' pitch-framing abilities (or lack thereof) in their individual defensive evaluations, and it really hurts Willson Contreras, putting his Fielding Runs Above Average total at -10.5. Anything around or below -10 is considered awful, and anything at or above 10 is considered excellent by that metric, so it really raises eyebrows to see Milwaukee's newly acquired Yasmani Grandal clocking in with a whopping FRAA of 23. That's a full 33.5-run differential from just catchers alone, a major factor in a nearly three-win advantage at the position and a big reason why the Brewers top the markedly improved NL Central with 89 wins.

Aging starting pitchers on the very low end of MLB average velocity (the 2019 Cubs are 28th of the 30 teams in average fastball speed of starters at 90.4 mph, ahead of only the Athletics at 89.9 and Mariners at 88.7) need framing and throwing from the primary catcher to give them more margin for error, not less. The inability to grab the extra strikes they need affects the whole staff too, leading to extra batters faced, more pitches thrown, shorter outings and higher bullpen usage.

Eighty-two is ugly and a bit of a shock to see, but it's hard to argue with how PECOTA reads the facts.

It's also just as true that human beings can perform at the higher end of their expectation ranges and get better at certain skills through experience and practice and that algorithms can overvalue data that's gathered imperfectly. This is just one estimation that ultimately counts for little, sobering as it may be.

Dan Bernstein is a co-host of 670 The Score’s Bernstein & McKnight Show in middays. You can follow him on Twitter @dan_bernstein.​​

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