Imagining if Luis Castillo had been a full-time right-handed batter

Luis Castillo is one of the most accomplished players in Marlins history. He spent nearly a decade as their starting second baseman, setting franchise records for career games, hits, walks and stolen bases. Fifteen years after being traded away, he remains atop each of those categories. No surprise, he was included in the inaugural Fish Stripes Marlins Hall of Fame class.

The three-time NL All-Star was clearly a South Florida success story, but was he really the best version of himself?

For generations, switch-hitters have been glorified by the baseball community. Spectators are in awe of the coordination required of them. Managers, who obsess about the platoon advantage, inherently trust them. It’s a superpower to be unaffected by the handedness of the opponent. Everybody wants to be a switch-hitter or wants to have one on their team, like Chipper Jones or Jorge Posada or José Reyes.

Luis Castillo was not a prototypical switch-hitter—he was the amalgamation of two completely different players. The contrast between these “identities” was amusing, but I think he would have been better off sticking with his stronger side.

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The exorcism of lefty Castillo

Original photo by Brian Bahr/Getty Images

Anything is possible in tiny doses. Jarlin García can be unhittable, Magneuris Sierra can be unstoppable and even Peter O’Brien can look like part of the solution!

But usually, the fun stops when the sample size expands. Luis Castillo batted more than 5,000 times in a Marlins uniform, 4,966 of those plate appearances during the regular season. After all of that, you would expect a very clear profile to emerge.

Well...these are Castillo’s platoon splits from 1996-2005:

• .287/.368/.325, 1 HR, 483 K in 3,672 PA as LHB vs. RHP
• .311/.378/.448, 18 HR, 138 K in 1,228 PA as RHB vs. LHP
• .279/.333/.361, 1 HR in 66 PA as RHB vs. RHP

With rare exceptions (most of them late in the 1998 campaign), Castillo always batted with the platoon advantage. Thanks to good contact skills, strike zone discipline and blazing speed, he consistently reached base safely at a high rate from both sides.

However, there’s a massive discrepancy in the power department. More specifically, his isolated power (slugging percentage minus batting average).

Castillo’s .137 ISO during this time period when facing southpaws as a right-handed batter was only slightly below the MLB average, but as a left-handed batter facing righties, he was a total anomaly. He posted the lowest ISO among all regular position players in the majors. The lone colleague in the same zip code, Otis Nixon, was notoriously punchless and nearing the end of his career at this point:

Stathead

The diversity of styles in baseball is part of its charm. Players can be effective with a wide variety of mechanics, philosophies and physical builds. But this is inarguable: righty Castillo was better than lefty Castillo.

What if he sacrificed the platoon advantage and played exclusively as a righty? Let’s attempt to convert the stats.

Walks & Strikeouts

The perk of switch-hitting is being able to see the ball well out of the pitcher’s hand, giving you as much time as possible to react. It’s easier to diagnose pitch types and lay off undesirable offerings. For this hypothetical, we need to take away that luxury from Castillo when he’s batting against right-handers.

Consider some league-wide trends from the 1996-2005 seasons. The MLB strikeout rate for LHB vs. RHP was 15.6%; the MLB strikeout rate for RHB vs. RHP was 17.8% (14.2% higher). Similarly, the MLB unintentional walk rate for LHB vs. RHP was 9.1%; the MLB unintentional walk rate for RHB vs. RHP was 7.0% (22.7% lower).

Applying that Castillo, we reduce the 412 walks (405 unintentional) he had as a Marlins lefty to 320 walks (313 unintentional) and increase his 483 strikeouts to 552.

Power

In RHB vs. LHP situations as a Marlin, Castillo homered in 18 of 1,088 of his at-bats (1.7%), but we cannot assume that he’d maintain that rate against right-handers. The uptick in whiffs would hurt in this department. Can’t hit it out of the park unless you hit it in fair territory!

Castillo is forecasted to go yard in 1.25% of at-bats after accounting for strikeouts. While that may seem microscopic, it yields 40 total homers over the course of the decade (instead of the 1 HR in actually had as a LHB vs. RHP).

Balls in Play

At this point in the process, we have to determine what to do with Castillo’s 2,708 balls in play.

From 1996-2005 in RHB vs. LHP situations, he singled on 26.3% of balls in play, doubled on 5.7% of balls in play and tripled on 2.2% of balls in play. Assuming these rates hold steady against same-handed pitching, those BIP become 712 singles, 154 doubles and 61 triples.

Before & After

Combining Luis Castillo’s RHB vs. LHP production, his actual production in 66 plate appearances when experimenting as a RHB vs. RHP and our projected RHB vs. RHP production for him, we arrive at this:

He goes from being a barely below-average hitter during the 1996-2005 seasons to comfortably above average. He dips in the on-base percentage department, but easily compensates with all the newfound quality contact that leads to more total bases.

It’s interesting to think about what Castillo’s overall performance could have been in ‘05. That year, he had extreme platoon splits (1.115 OPS vs. LHP, .650 OPS vs. RHP). Mashing from his strong side the whole time, maybe he challenges for his first-ever NL Silver Slugger? Do the Marlins finish close enough to a postseason berth to convince ownership to keep their veterans together for one more year? And even assuming Castillo gets traded anyway, what kind of prospect package would he have commanded on the market? (In real life, the Fish received Travis Bowyer and Scott Tyler. Neither made a regular season appearance for them.)

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Steve Mitchell-USA TODAY Sports

My hunch is that right-handed Luis Castillo would have been slightly less successful than projected here. As a lefty, he got down the first-base line as quickly as anybody in the league. He perennially ranked among MLB leaders in infield hits while rarely grounding into double plays. Moving to the other side of the plate full time ought to cost him on bang-bang plays.

Castillo’s stolen base total would be lower, too. Fewer times on base and a greater ability to put himself in scoring position limits his opportunities to steal and definitely shrinks the gap between he (281 SB) and Hanley Ramírez (230 SB) in the Marlins record books.

That being said, I believe it would’ve been best for all parties if Castillo simply trusted his swing.