The Giants Are Up to Something

Have the Giants hacked defense?

The Giants’ surprise 2021 maybe shouldn’t have been so– after all, San Francisco found themselves in a playoff race in 2020 despite struggling out of the gate to a 9-16 record.

This year’s squad, however, has still exceeded all expectations by spending over 130 days in first place (as of Monday) with the most wins in all of MLB, despite playing in what is probably the most competitive division in the league.

The Giants have done it through offense, with the best production in years from some of their core veterans, and through career bests from journeymen and young players alike. They’ve done it through breakout pitchers no one saw coming and continuing to get the absolute best from veteran free agents. How, exactly, the Giants have been able to do so remains a bit of a puzzle. On the pitching side, they’ve almost completely abandoned curveballs, for one. And on offense, it seems that career-bests in years from the likes of Crawford, Posey, and Belt may have something to do with how they’re approaching batting practice if you believe the team.

All these career years can’t be a coincidence. The Giants’ use of platooning and mixing-and-matching players is surely a contributing factor, but the team has also seemingly hacked player development, at least at the major league level. No aspect of the Giants’ season demonstrates that better than their defense.

Defense is notoriously difficult to quantify. From everything we can quantify, though, it sure seems like almost all of the Giants are taking steps forward in both their results on the field in terms of preventing outs, but also individual skill levels.

Looking at the team as a whole, the 2021 Giants are on pace to almost double their highest ever Outs Above Average for a season since the statistic first became available. (Outs Above Average is a range-based fielding metric that measures plays made and their difficulty. Further explanation can be found here). This Giants team has so far surpassed their OAA than their total from all of 2016-2020, good for third in baseball. 

With that kind of outlier, you might expect that there’s some philosophical, team-wide change to defensive positioning or approach, but that doesn’t seem to be the case with the Giants. Their positioning in terms of both depth and angle is fairly average and in line with the league mean. 

It also hasn’t been some kind of team-wide tactical approach to defense either. The Giants don’t shift much at all, ranking 22nd in overall shifts, and shifting right-handed batters less than anyone except the Padres. Instead, San Francisco’s improved defense seems to be coming almost entirely from skill development from individual players that we can measure– and almost every regular player. 

Brandon Crawford has a career-high in Outs Above Average. Crawford has always been a very good defensive shortstop, but this year is tied for fifth in baseball with 14 OAA (again through Sunday). Brandon Belt had good defensive years initially with the Giants but has been average or just below each year since 2017, and now is posting his highest outs above average since then. 

Darin Ruf, never a glove-first first baseman, is also posting a career-high 5 outs above average, never previously having broken 0 in his previous stints in the majors (though it should be said he was splitting time between the outfield and first in limited time with the Phillies in 2016, the last year OAA was available before playing in Korea). Ruf now is second among all first basemen, behind only Gold Glove winner Anthony Rizzo.

Mike Yastrzemski, on the other hand, has never had an above-average season in the field in his short time in the majors (-4 in 2019), and yet this season has posted eight outs above average, tied for eighth among all outfielders so far. He has gone from a below-average outfielder to one of the very best in two seasons with the Giants. 

The Giants are making strides at defense, but we know it’s not tactical or strategic positioning. It must be individual skill development, but to what can that be attributed?

Outs Above Average tells us that Giant fielders are making more plays and more difficult ones, but not necessarily how. Outfielder defense in San Francisco may provide a clue. 

Outfielder “jump” is a little complex to explain, but essentially it can be thought of as the feet gained or lost on a play due to a fielder’s reaction and the route they take. Among the Giant outfielders that have had the opportunity for at least ten catches with 90% catch probability or less, all of them have above-average jump feet vs. the average:

Player Feet vs. Average
Austin Slater 1.6
Mike Yastrzemski 2.3
Steven Duggar 2.5


What’s more, these are career highs for each outfielder. Austin Slater was below average in his first three seasons and now is in the top 25% in the league. Yastrzemski has hovered around average (1 foot above average, and 0 in 2020) in jump, and now is in the top 10% in the league. Similarly, Steven Duggar, while always above average as a center fielder in OAA, has increased his previous career-high in jump by nearly a full foot, also placing him in the top 10% of the league.

The Giants’ outfielders are seemingly making pretty significant gains in their routes and reactions and it’s led to more outs for the defense. Unfortunately, infielder reaction is more difficult to quantify, but as we’ve demonstrated, the Giants’ infielders are making similar strides in terms of the outs they’re recording above the MLB average.

I think these results make the case for the Giants’ player development being the secret sauce to their resurgence, rather than player acquisition or tactical approaches. The defense is reacting better to the ball, and that can’t be attributable to their positioning or approach. In the same way, I believe that lends credence to the idea that the Giants are also showing improvement at the plate through simply improving their contact and hitting skills rather than taking a different approach at the plate or hitting philosophy. It may be that the Giants are preparing for defense differently– with more “realistic” fielding practice, or at higher velocities or sharper trajectory than traditional fungoes or fly shagging.

It’s easy to roll our eyes at “old school” justifications for improvements, such as the Giants coaches’ assertion that they’re simply practicing differently or harder. Our default may be to search for changes in swinging-strike rate, or assume that analytically-justified defensive shifts are responsible for any major swings in changes, but I’ve become a believer that the Giants may have hacked a way into improving players’ underlying skills. The career-bests both at the plate and in the field are too much to be explained away by coincidence or a change in approach, particularly when they’re happening to longtime veterans.

Photos by John McCoy, Larry Placido & Brian Rothmuller/Icon Sportswire | Design by Michael Packard (@designsbypack on Twitter @ IG)

Sean Roberts

Sean Roberts is a baseball columnist for Pitcher List. His work has been featured on Baseball Prospectus, the Hardball Times, and October. He's still getting used to the DH in the national league. @seanroberts.bsky.social

2 responses to “The Giants Are Up to Something”

  1. JT says:

    That sounds about right. They’ve hacked returning hitters from the IL ready to hit right away, not in a few games after they get their timing back. They’re saying it’s the type of prep they’re doing. Ditto pinch hitters. Gausman, a pitcher who pinch-hit, won a game with a sac-fly after spending the preceding inning in the cage hitting against high fastballs, which is what the reliever was likely to throw at 3-2. It worked.

  2. Chris says:

    I will tell you how they hacked infielding. In the last few years, the most inspirational amateur infield development guys have been the Dirt Brothers, the assistant head coach at Yale (Tucker Frawley, who led them to the highest fielding percentage in college baseball), and Kai Correa. The Twins brought Frawley into their org, and the Giants hired Kai Correa and made him bench coach/infield and base running coach. He’s tremendous. All three coaches are so into the process of building routines from the ground up. You can see videos online of Brandon Crawford and the guys working with him in the gym during lockdown like high school ballers, totally buying into the process. https://www.mercurynews.com/2020/01/22/from-d-iii-to-the-major-leagues-kai-correas-unusually-quick-journey-to-the-giants-bench/

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