Plate Discipline and Co. has a new leader

As an old saying goes, you’d better be lucky than good. That applies to pretty much everything, from poker to school exams, from life to baseball.

A batter has his own merits and shortcomings, but sometimes he’s just another pawn on the hands of fate: if Baseball God smiles upon him his bloops will fall in no man’s land for singles, his groundballs will sneak through shifts and well positioned infields and every flyball will be carried by a favorable wind for a couple feet more, making a flyout into a HR. Or else, Baseball God could laugh over him in all his cruelty: bloops? Jose Iglesias. Groundballs? Still Jose Iglesias. Absolute nukes? Gregory Polanco.

What’s to a batter then? What are his weapons against that miracle/curse that we like to iconize as BABIP? Well, getting the process right is a start, and by process I mean one of the darkest arts in all of baseball, a trait that only the elected have mastered: plate discipline.

Among all of the tools in a baseball set “plate discipline” is the most obscure and closest to the fearful intangibles, that will to win, grit, closer mentality yadda yadda yadda. It’s also one of the most important skills to have: a bat can slump but an eye does not. Can’t buy a hit? Walk your way to first and let the others bring you home!

You all know the savants, those few good men who acquired the eagle eye for the strike zone: Joey Votto is the cult leader of the OBP church, such that “It’s not a strike if Joey says it’s not”, Carlos Santana is not bad too, Juan Soto is the new acolyte and Max Muncy had an epiphany.

Who is paving the way now though? Who preaches the way of the zone better than all? Here’s a couple of candidates:

Wildly similar profiles, a common story: these guys know their strikes. If I had to choose a proxy of “plate discipline” I’d pick Z-Swing% minus O-Swing%, so the net difference between the rate at which a batter swings at pitches in the zone and the one at which he chases out of it. Good news is, these two are pretty good at it: the ATL batter swings and chases less, but the HOU hitter is better, a 52.3% difference in %points that is best on baseball, the lowest CSW%, Alex Fast’s creature, in MLB and mirroring production numbers.

Atlanta’s batter here is an easy guess: who is the Brave most adept at not chasing while barreling and hitting a fair bit? Ozzie Albies is too swing happy and so is Ronald Acuna Jr, the only other certified great Brave, sorry Austin Riley, is none other than Freddie Freeman!

But wait, does Houston have a Freeman at home? Yes, and that’s not the first name you’d throw out: it’s not Altuve, who likes to swing at pitches 5 ft over his head, nor Gurriel, although he’s chasing far less, nor Brantley or Correa. Houston’s own Freddie Freeman stations in RF, hopefully not in CF, and is someone I already got to know.

How the turn tables, Kyle Tucker?!

Last time we saw Tucker he was dealing with a bad hand, his peripherals firmly on the red but his actual results middling such that the luck factor was dragging his numbers down. That gap hasn’t fully closed yet, most of his Xstats are 40–50 points over his real ones, but his Savant page is still a ton of crimson with shades of white:

Tucker exists in the dimension between above average and elite: he hits the ball fairly hard fairly often, finds the barrel quite well thanks to his flyball-oriented approach and avoids Ks by means of bat. He doesn’t walk much, an aggressive swinger with high contact rates he usually won’t be there for a 3 ball count, he chases some but his expected production is among the best in all of baseball, 95th percentile or better in xwOBA, xBA and xSLG.

While we’re at it he’s also a more than competent defender, a solid RF with a couple of OAA he can cover a ton of real estate thanks to quick reactions and first step compensating for imperfect routes and an arm that lost firepower since his Minors days. So did his legs, with a -0.4 ft/s Sprint Speed from 2020, still he’s an above average fielder, not in CF though, and an acceptable baserunner.

A complete package, one that comes with a gift: Tuck is seeing the ball as well as anyone. His Z-Swing% is second only to Albies but his O-Swing% is much lower, in the top 10 of lowest rates making him, so far, the winner of the “Joey Votto” trophy for discipline: swing a lot at pitches in the zone, don’t swing at those out.

That’s not to say that every ball is a bad pitch to hit, ask Altuve or Ohtani if they mind seeing a ball head-level, or that any strike is a good pitch to hit, pitcher’s pitches do exist, but being able to discern offerings and swing accordingly is a feat that must be celebrated.

Before you think about it, this is not a case of “phantom discipline”, an unforeseen growth in bases on balls due to an indiscriminate decrease in Swing% for both pitches in and out of the zone, the Gurriel and Grandal cases, quite the opposite:

Tucker is swinging at a career high rate of pitches and whiffing at a career low: when his bat flies in the zone he rarely misses, you can get him to chase but in that case too he’ll put good wood on the ball trying to reach first in any way he can. Most notably, he’s also maximizing his performance by making optimal in-zone swing decisions:

Throw him something in the middle, up/center/down doesn’t matter, and he’ll let it rip, watch out for his ability to get his arms extended and line or go oppo on pitches in the outer third and don’t hang a breaking ball down and in or he’ll golf it to the pull side. There are not many holes in Tucker’s swing, if anything going up the ladder with gas seems to be the choice, but if you want to beat him it’s going to be a duel in the zone, stuff against power, as he doesn’t chase the down/away sliders as other lefties tend to do.

All signs point to Tucker being next in line to be one of the greats: HardHits and Barrels are there, there’s no swing and miss to be found and he won’t lose to a pitcher’s trickeries, all those breaking and offspeed stuff tumbling out of the plate.

If that’s so why is he still behind the 8-ball, chasing that greatness his underlying stats foresee? There’s a sole flaw in Tuck’s amazing season so far: pitches right down the middle.

Whereas his swing decisions are almost perfect, particuarly on the Heart zone with a gaudy 90% Swing, his results are not: meatballs are called as that for a reason, pitches that should be eaten alive, runs that are much needed nourishment for an offense. Tucker picks up his cutlery ready to eat but his bites are not that big, so that on offerings he should destroy to outer space he’s settling for a munch, a single and the occasional extrabase hit.

There’s a wide gap from what it is and what should be right where he swings more, the middle meridian of the strike zone where damage happens and that’s partly a bout of bad luck partly an approach matter: Tucker, once a pull monster, is now exhibiting a more balanced hit pattern, not disdaining the opposite field and spraying the ball all over the ballpark, to the extent that he sacrificed a smidge of power for a lot more contact.

If he was the old Tuck, a dead pull hitter, he’d have a couple of bombs more if fed the same amount of middle-middle pitches, but he wouldn’t probably see a lot of them as he’d be much more susceptible to chase, miss and go out the way of the K.

On an Astros offense that is rewriting records, firmly first in all of baseball in Runs per Game and heading most offensive categories apart from HR, Kyle Tucker is the face of improvement: once a masher with swing and miss tendencies, he’s now a complete hitter, a contact guy who also has 30+ pop, walks a bit and strikes out less than average.

Along with Altuve’s resurging power, Gurriel’s patience, Correa’s contract season, Brantley’s professional hitting and Yordan being Yordan, Tucker is one of the pillars of Houston’s lineup, a squad that can only be stopped by Max Scherzer’s disgusting stuff and the deadly encounter between pitch-to-contact and abysmal BABIP.

The battle with luck is not over Kyle, but the process has never been so right: keep on laying off breaking stuff away and cheat on those meatballs to bring the feast to Houston!

All stats from FanGraphs, graphs from Baseball Savant, data updated to August 5th.



Italian baseball stathead. I’ll write about MLB, Nippon Professional Baseball and Korean dramas/shows. A lot of graphs, Astros related content and references.

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Alessandro Zilio

Italian baseball stathead. I’ll write about MLB, Nippon Professional Baseball and Korean dramas/shows. A lot of graphs, Astros related content and references.