The Padres have lost each of their last four games against left handed starters and that is no fluke. Part of their struggles we’ve discussed: they’ve faced a well above average cohort of left handed pitchers so far this season. That trend continued this past week when they faced Braxton Garrett, Cole Ragans, and Tyler Anderson. Even Patrick Sandoval, who came into Tuesday’s start with a >5 ERA, has pitched to a 3.76 FIP on the season and is fresh off a quality start against the Yankees where he struck out seven and gave up only two hits across six innings to the best lineup in baseball. None of these lefties were truly an easy matchup. This is not to hand wave away the losses, there is a problem here. Even when the Padres schedule lightens up and they face easier left handed opponents, there’s reason to think they may still struggle.
Warning: back of the envelope math ahead.
A Durable Trend
One of the most durable year to year statistical observations is the platoon splits when left handed pitchers are on the mound:
This tendency affects the very best left handed hitters:
And even the very worst left handed pitchers in the league tend to enjoy a healthy performance boost against lefty bats (2023 stats):
But what’s interesting is that the typical same side platoon penalty (SSPP) to a left handed batter facing a lefty pitcher is of greater magnitude than the opposite side platoon bonus (OSPB) for a right hander facing a lefty pitcher:
Succinctly: left handed hitters are punished more than twice as harshly as right handed batters are rewarded when facing left handed pitchers, generally. It’s from this observation that you start to see the real danger for the 2024 Padres: Left handed hitters are naturally going to be disadvantaged against left handed pitchers. When you pair that with right handers who are producing poorly at baseline, the modest performance boost to the right handed bats from the OSPB is not enough to make up for the penalties to the left handed bats.
Applying this to the hitters in the Padres lineup (absent Jurickson Profar who is a switch hitter): you can see the expected trends have held true versus left handed pitchers across their careers:
This looks to be a viable lineup against left handed pitchers if the hitters were mostly performing to their career average OPS. But this is precisely the problem the 2024 Padres are facing: Several of the Padres right handed hitters are not getting to their career OPS to begin with. In fact the right handed batters are largely not even getting to their 2023 numbers, a year which was a down year for each of their three most important hitters:
Tatis is the lone right handed mainstay in the lineup that has gotten to his 2023 OPS, and he’s still miles away from his career .880 OPS. Machado is well off his 2023 pace which was well off his career pace. Xander Bogaerts is sidelined until near the end of the season, but is listed here as he’s culpable for the Padres early season struggles against lefties. Luis Campusano is playing below replacement level. And Kim just hasn’t performed as well as last season.
So here’s a -very- simple exercise to visualize why the above conditions imply the team will continue to struggle significantly against left handed pitching. If you assume that a player’s career SSPP or OSPB is applied to their 2024 OPS you would have the following projections against average left handed pitching:
The team’s actual performance has not been this high which may be due to the quality of opposing lefties they’ve face so far. But the really troubling thing is that the lineup projections above are the best case scenario for a team at this baseline of performance, and that’s pretty mediocre production. This suggests even if competition wanes a bit the lineup’s performance against average left handers is going to be disappointing.
Game Theory
Summarizing from a game theory perspective: you should expect left handed hitters to incur harsh penalties against even mediocre left handed pitchers, which in theory can be compensated for by the moderate platoon boosts to right handed hitters, but modest performance boosts applied to very poor baseline right handed hitter performance is not going to make up for the kneecapped left handed hitter production. Add onto this that the Padres have drawn a well above average pool of left handed starting pitchers and you have a fairly complete description of the 2024 Padres struggles against left handers. More distressing, though, you have a trend that appears poised to follow the team through the entire season unless the performance of the right handed bats can be improved. Indeed, if there isn’t improvement in the baseline right handed hitting performance this would be a weakness easily exploited in the postseason if the team was lucky enough to survive that long.
This is a problem.
There's 3 things I'd want us to do to fix this LHP problem:
1) DFA David Peralta, call up Eguy Rosario, and play Eguy for Crone on LHP days. (Crone is OPSing .480 v LHP so far)
2) Send down Azocar, call up Locastro or Mercado (both 900+ OPS v LHP in AAA so far), and play them for Merrill on LHP days. (Merrill is OPSing .424 v LHP so far). I'd opt for Locastro who can also has some speed, steal a bag, play decent D. Locastro just seems like an upgrade all around over Azocar for me. Mercado might have more career success vs LHP, and is also a good pick.
3) Trade for a catcher (Elias Diaz, Danny Jansen, Shea Langeliers, Kyle McCann, etc) and have Campy be the backup moving forward. If we can't do that, consider playing Higgy vs LHP. (Campy is OPSing .339!! v LHP so far -- not to mention metrics show he's the worst defensive catcher in MLB + a bottom 3 starting catcher by WAR.)
Lineup v lefties could look like:
1B Arraez
RF Tatis
LF Profar
3B Machado
2B Rosario
DH Solano
SS Kim
CF Locastro/Mercado
C Higgy / (or trade piece)
At minimum I feel like we have to make the Rosario move. He'd make a big difference right away.
Longer term we need to figure out a solution at catcher, because Campy ain't the answer for the next 3 years while we wait for Salas (who also could end up a bust anyway).
If Preller wanted to go crazy he could also trade the farm for Robert Jr to play CF lol.