There are, naturally, reasons why the piggyback-style rotation has caught on in the low minors while failing to score more than a random cameo here or there at the upper levels of professional baseball. Traditionally, a team carries seven, sometimes even eight, bullpen arms. Downsizing the cleanup crew to a four-man unit would require a complete reset to the philosophy of what makes a viable bullpen arm. But it’s certainly doable! Well, let me rephrase: with the right personnel on board, it’s certainly doable. Accomplishing this will require reassessing bullpen strategies.
Part 1: Piggyback Rotation
The modern bullpen is built to run deep. When the average manager walks out to the mound for the first time in a game, he has seven different weapons in his arsenal to deploy. That means several important things:
- If one of those weapons serves a very specialized purpose, such as retiring a single left-handed batter, that’s perfectly okay. Such a purpose is sure to come up, and you’ll be glad to have an ace up your sleeve then.
- If one of those weapons turns out to be a dud on any given night, well, that sucks regardless of circumstance. But you’ve got the luxury of the quick hook. There’s no need to ride it out with a pitcher who is struggling to find his groove. Just toss him on the slag heap and pick another candidate from the list before things get ugly.
- If one of your pitchers can throw one or two pitches really well, but never developed that third offering, you can use them in the bullpen and never worry about a hitter seeing them for the second time in an hour or so and becoming too familiar with their stuff.
- Following these three points, the modern bullpen tends to function as a safe haven for pitchers who are unreliable or have a short in-game shelf life, but who balance out those negatives with a high strikeout rate or elite performance against one side of the platoon split.
A four or five-man bullpen required by a piggyback rotation, on the other hand, does not have the same luxuries, so the type of pitcher you’re looking for is going to look different. The elite tier of relievers, the game’s Chapmans, Jansens, Brittons, and Kimbrels, would all look great in either bullpen, because they’re great at everything while having precious few flaws to their game. But as you move away from the elite, and towards replacement level, the type of player that can fit in either system start to diverge.
I’ve come to identify three different traits that play pivotal roles in making the ideal reliever for a piggyback rotation.
- Stamina. A five-man bullpen will get burned to cinders in a hurry if its pitchers are getting wasted on seven-pitch appearances. That means that going longer than an inning out of the bullpen would, ideally, be the norm for a reliever, as opposed to the anomaly it tends to be now.
- Platoon splits. Going hand-in-hand with that last point, bullpen arms behind a piggyback system don’t have the luxury of specializing as a LOOGY or ROOGY. Pitchers with extreme splits tend to come in for one batter more often than not, which means that, in this system, they’re useful only as trade bait.
- Command. A shorter bullpen means that a dud outing from a reliever hurts the bullpen, and the team, even more. Therefore, the relievers we’re stocking in our bullpen should not be the sorts of guys who are prone to melting down regularly. Whiff rate plays into this too, as do exit velocities, but ask any pitcher what the number one cause of a meltdown-level outing is and they’ll immediately answer back “walks.” The modern bullpen has become something of a sanctuary for pitchers with electric stuff and tenuous control over it, but this is due in large part to the sheer volume of bullpen arms available on a game-to-game basis. If a wild reliever doesn’t have it on any given night you simply yank him, bring in somebody else, and roll the dice again. Remove that luxury, and it becomes more essential than ever that our bullpen arms be capable of locating their pitches in the strike zone reliably.
Upon this reflection, it makes a lot more sense why only the 2012 Rockies, the quintessential example of a downtrodden, desperate pitching staff, were the only team to entertain the piggyback rotation. People tend to be resistant to change, and the piggyback rotation brings with it sweeping, unprecedented changes in how the entire pitching staff is stocked, evaluated, and deployed. It is, in short, a complete departure from everything that has ever been done in baseball. And that is exactly why the rebuilding Brewers would be so smart to implement such a system. In this sense, completely overhauling the responsibilities of the pitching staff doesn’t sound like such a daunting obstacle; rather, it looks like the road to success just waiting to be paved.