For let’s say 50-65% of the history of the sport, most of manager strategy followed convention. By convention I largely mean that during any X scenario, we would expect Y, and not Z or A or B or C. When a fast runner is on first base, we expect them to run. When any hitter is up (or than any extreme left-hander), we wouldn’t expect a shift. When the ninth inning rolls around, we expect the closer.
As time went on, those rules started to be eroded, but a completely new set of orthodoxy emerged. We now would expect the best reliever in the highest leverage spot, or a shift corresponding to spray no matter what. Four-man outfields and five-man infields are also becoming more and more common, and bunting has become less common. You get the idea.
Yet the one idea that’s been around as long as The Book, but has only caught on at a slow rate, has been the Waxahachie Swap. This strategy, in which a manager puts two pitchers (one on the mound and one in the field) in and swaps them to utilize platoon advantages throughout the inning, has been in use in some form or fashion in modern baseball since the 1950s, and has been around as a concept since the 1880s.
In a recent example that doesn’t fit squarely into the definition, we saw Vince Velasquez on Friday night enter as the left fielder in the 14th inning against the White Sox. Not only did he enter, but he recorded an outfield assist to the tune of a 94.7 mph zinger to home plate:
Normal baseball stuff. pic.twitter.com/9xOnd2ff8f— Philadelphia Phillies (@Phillies) August 3, 2019
This was more out of necessity than it was out of strategy, and I guess you could say... does it even classify as a Swap at all? Roman Quinn, a position player, is pitching, and Velasquez technically was not supposed to get the ball given it was bullpen day, nor was this employed for platoon advantage purposes. Yet if Quinn couldn’t pitch for whatever reason, one would guess Velasquez would have to enter.
It’s a Swap Proper in the sense that managers in the past just wouldn’t have structured their bullpen innings such that no one would be available except a pitcher to sub in in the outfield, so I’m going to plop that into the category of being closer to Swap than not.
All of that is besides the point, which is actually two-fold. The first is that as analytical as the game has gotten, and with every conceivable number that’s available, is the Swap actually a good strategy? Putting aside the necessity inherent here, would it make sense even if it was voluntary? Our old friend Russell Carleton says... maybe:
“It’s possible that if the two pitchers alternated over a couple of hitters, and maybe made a couple of trips back and forth, thus grabbing multiple extra plate appearances with the platoon advantage, it could turn a profit. However, that opens a team up to more risk for that ball that finds the pitcher in left field. I can see why it doesn’t happen very often. Just because something feels like living dangerously and isn’t done often, it doesn’t make it a ‘good, but underappreciated strategy.’”
Bingo. While there could be the advantage of a platoon split, or in this case of basically being able to use every reliever earlier and using the last pitcher as a backup outfielder, the actual benefit to say... just saving that last reliever for that situation instead of Roman Quinn, is razor-thin in terms of cost versus benefit.
Clearly this is why the strategy is barely used. Rob Neyer, as of 2009, said it had only been used 21 times in the modern game, and there have only been 35 in baseball history. More importantly, from 1909 to around 1950, it was never used at all, and used only sparingly in the 1950s and only a handful of times in the 1980s.
Maybe the 19th century and its weird conventions had a point; to be fair, they employed all kinds of funky strategies and rules that are rightfully never used again. At the same time, though, there are certain intuitions they may have had back then that could be completely correct, and this is one where the math at times does work.
If the platoon advantage—or in this case, the advantage you gain by saving a pitcher as a backup outfielder/pitcher of last resort—is significant enough and you have internal defensive metrics to determine that a pitcher in the outfield won’t hurt you on range or arm runs, then it works out in the sense that it should be used more than once a year. Teams are still pretty risk-averse, though, and especially with pitchers, as Velasquez is the perfect example as someone who has yet to toss more than 150 innings in a season. If you pull your arm out, then you can guarantee the numbers doesn’t add up.