To wrap up our series on the merits of the four-man rotation, let's look at some of the ancillary benefits of making the switch:
The four-man rotation simplifies a starter's between-start schedule. Most teams have their starters throw on the side once between starts, but no one really knows whether it's better to throw on the second day after a start, or the third. It's not even clear whether starters should throw only once. In Atlanta, Leo Mazzone has had continued success doing things his way: he has his starters throw twice on the side between starts instead of once. (He does this because he feels it gives the starter the same increased sharpness that comes from working on three days' rest.)
In a four-man rotation, there is no dilemma. A starter rests on day 1 after a start, throws on the side on day 2, rests on day 3, and is back on the mound on day 4.
If you need fewer starters, you need fewer pitchers, period. Moving the fifth starter to the bullpen gives a team the luxury of having a long reliever who can take the pressure off the other relievers, three and four innings at a time. A team that carried six relievers would only need ten pitchers – you know, the way they did things back in the 80s. Even if a team needed to carry around a seventh reliever as a crutch, they would only require 11 pitchers. By carrying one fewer pitcher, a team would open up an additional roster spot for a pinch-hitter, or a pinch-runner, or a defensive replacement. Plus, in the National League, teams that go to a four-man rotation and pull their starters earlier in the game would increase the number of the pinch-hitting opportunities, thereby slightly improving their offense.
Earl Weaver never carried more than 10 pitchers at a time, and frequently kept just 9. In so doing, he was able to carry as many as seven bench players, allowing him to mix and match talented role players like John Lowenstein and Terry Crowley and Benny Ayala. He was able to start a defensive whiz like Mark Belanger at shortstop because he had enough bullets on his bench to pinch-hit for Belanger if the Orioles were losing late, and have the defensive replacement on hand as well.
Today, some teams carry as many as 13 pitchers at a time, leaving room for just four bench players in the NL, three in the AL – one of whom has to be a backup catcher. This hamstrings a team's in-game flexibility, limits tactical options late in the game, and provides little depth to weather injuries.
Switching to a four-man rotation is a move designed to benefit the pitching staff, but it helps the offense as well.
Your best pitchers not only throw more innings, they throw more relevant innings. Working in a five-man rotation where they are limited to 33 or 34 starts, the only way most starters can reach 220 or 230 innings in a season is to throw a good number of innings in games that are already in hand. Just looking at games from this past weekend: Freddy Garcia tossed the 7th and 8th innings of a game the Mariners were leading 12-4; Jason Schmidt pitched the 7th inning with the Giants leading 7-2; Randy Johnson tossed the 9th inning with the Diamondbacks leading 7-0; Tim Hudson pitched a complete game even though the A's were ahead 11-3 after 3 innings.
Three of these four pitchers are among the best starters in the game, and Schmidt is no slouch. All but Schmidt are on pace to throw over 220 innings this year. But as these examples show, some of those innings are being used in low-leverage situations that provide little benefit to their team, because any major-league pitcher worthy of a roster spot should be able to protect a five-run lead with two innings to go.
By giving starting pitchers an additional seven or eight starts per year, you guarantee that those innings will have meaning; after all, every game starts with a tie score. With more opportunities to pitch, there is less need for a starter to accumulate innings by working deep into ballgames where he has a comfortable lead, allowing the less-experienced pitchers on the staff the opportunity to get some innings in low-pressure situations.
More regular work may help young pitchers develop more quickly. We're talking about the great unknown here, but isn't it possible that young pitchers may be even fresher on three days' rest than veterans? Examples of great starters who required extra rest as they approached 40 are myriad, with the most recent example being David Cone. You rarely hear of the 21-year-old fireballer that needs an extra day of rest, though.
The dilemma of how to best develop pitchers while keeping them healthy has been vexing baseball teams for decades. Because the minor league season only runs through Labor Day, there are fewer innings to distribute among minor league prospects. As every organization wants its best prospects to get as much repetition as possible, with only 26 or 27 starts available, the only solution has been to allow those prospects to pitch 6 or 7 innings a start. For a 22- or 23-year-old major league starter, that workload is dangerous; for a 20-year-old prospect in A-ball, it borders on criminal negligence.
We have already seen at least one influential baseball man, Grady Fuson, take a different tack. In order to get his charges as much work as possible while keeping them healthy, Fuson has experimented with a modified version of the four-man rotation. In his system, eight pitchers are split into four pairs, working every fourth game, with one member of the pair starting, and the other relieving after the starter has reached a very conservative pitch limit, somewhere around 80 pitches. The two pitchers then switch places the next time through the rotation. Two or three pitchers are made permanent relievers to fill in the gaps along the way.
Fuson has hit upon something very important: based on the existing research, it seems safer to allow young pitchers to work on less rest than to allow them to throw 110 or more pitches in a game. The organization that decides to switch to a four-man rotation can start at the minor league level, either by using the Fuson formula or simply going with the traditional four-man rotation, as long as those starters are placed on very strict pitch counts. With 33 or 34 starts in a minor league season instead of 26 or 27, those starters won't have to pitch 6 or 7 innings a start to get their innings in. Even averaging only 5 innings per start, a minor league pitcher in a four-man rotation could throw 165 or 170 innings a season, which is as much as most minor league starters rack up today.
The days of the five-man rotation are numbered. Baseball strategies are governed by the same evolutionary processes that guide strategies in any business: those that are successful are kept, while those that are not are discarded. Major League organizations are learning that the best way to keep their pitchers healthy is to restrict their pitch counts. Eventually, some bright guy in a major league front office is going to realize that if the solution to keeping pitchers healthy is to limit their pitch counts, maybe limiting their starts isn't part of the solution at all.
And once that light bulb goes on, the only thing that will keep teams from experimenting with the four-man rotation will be inertia, that pervasive tendency among baseball teams to keep from rocking the boat and putting their ass on the line. Don't discount that inertia, for it is a powerful thing – but eventually, it will be overcome.
At some point in the next five years, I am confident that we will see the return of the four-man rotation. It might come from the Reds, who have a manager that's proven he's ballsy enough to try the maneuver, a GM who is willing to consider anything that might make his team better, and a pitching coach who's worked wonders building starting staffs out of spare parts. It might come from another team, one that is both creative and desperate enough to clear away the mothballs from a concept that worked well 30 years ago, and can still work well today.
The four-man rotation is poised to make a comeback. As far as I'm concerned, it can't come back soon enough.