Everywhere you look, as the 2017 MLB season gets underway, there is a focus on the bullpen. And it’s for good reason.
By a manager bringing in a fresh arm and dictating the pitching matchup, relievers provide a clear edge. But how can managers maximize that advantage? Is there such thing as a “perfect” bullpen? While no team is ever going to shut out every opponent, statistical research can tell us how to consistently and most effectively put the odds in the pitcher’s favor, even if some of the ideas are a bit unorthodox. In that way, perfection is absolutely achievable.
It all comes down to four keys, and while none are hard-and-fast rules, the one requirement to optimizing your bullpen is thinking outside the box.
Use a reliever in the first inning on the road
As crazy as it may sound, one idea presented at this year’s Sloan Sports Analytics conference by Willie K. Harrison, an assistant professor at University of Colorado — Colorado Springs in the electrical computer engineering department, and John L. Salmon, an assistant professor at BYU in the mechanical engineering department, suggested you should start a “leadoff pitcher” on the road who pitches only the first inning.
Their research, presented in the paper “Bullpen Strategies for Major League Baseball,” posits the first inning makes up approximately 21 percent of the overall difference in scoring potential between the home and visiting team, and, using a pitcher for the first inning, or even just the leadoff hitter, helps level the playing field.
“You could, theoretically, take away roughly nine percent of the home field advantage by doing that,” Harrison explained. “Managers aren’t using the full bullpen in any given game, and for the majority of all games pitched you have someone left over, so why not use them to optimize this strategy.”
It makes sense. A reliever, typically because they have one or two good pitches, is more likely to go “all out” early, knowing he won’t be used for more than one or two innings or work. Starters, by comparison, need to pace themselves so their fastball can still have enough velocity in the later innings.
By starting a reliever, managers can select the pitcher best suited to shut down the top of the opposing order. It also allows the starter to work later into the game while limiting the number of times the top of the order sees his stuff. Limiting that exposure is key and the numbers back it up.
Starting pitchers are also less effective after pitch 50 than they are before pitch 50, and even worse after pitch 75, giving us one more reason to not see a starter pitch too deep into a game.
By using a reliever for the first inning, you can extend your starter into the seventh inning before the lineup turns over for the third time. But that’s when managers need to dive into the pen again. And when they do, they shouldn’t be afraid to fire their best bullet if a crucial situation arises before the ninth inning.
Closers are a thing of the past
This lesson has already started to take hold, with Andrew Miller used by the Cleveland Indians and Terry Francona much earlier in games during the last postseason. That’s the savvy move. In an optimal alignment, a manager’s best reliever should be used for the innings with the most on the line. And, according to the leverage index (LI), that happens more often than just save situations in the ninth inning.
The leverage index measures the swing of the possible change in win expectancy. An LI of 1.0 is average, with high leverage classified as 2.0 and above and low leverage below 0.85.
In 2016, there were 1,015 innings which had a medium or high-leverage (leverage index of 1.5 or higher) save situation. But there were also 521 innings with high-leverage hold situations and another 764 innings with a high-leverage situation that was neither. Having relievers who can pitch in clutch situations — no matter when they occur — is crucial. After all, you might not be able to get to your closer if you can’t find someone to get you out of a bases-loaded jam in the middle innings of a tie game.
You need two specialized left-handed relievers
Over half of all plate appearances last season featured a batter facing a pitcher of the opposite handedness, but from an ideal pitching standpoint you’d want to match up righties against righties and lefties against lefties. Though it’s hardly anything new, the splits from last season bear this out, with left-handed batters having the most trouble against left-handed pitchers.
The difference is small — one-half a run per 100 plate appearances — but notable. And again, since we’re striving for perfection, you’ll definitely want one or two lefties in the pen. And for the perfect pen, you’ll definitely want a second southpaw, since a lefty-heavy top of the lineup may require you to start one of your left-handers in the first inning using the “leadoff pitcher” approach.
Twelve pitchers is enough
After a year that saw the highest usage rate of relievers in history, you may think it wise to carry another pitcher, opting for 13 arms when most MLB rosters usually only carry 12. Even with the declining number of quality starts — six or more innings with three or fewer earned runs — on the decline (2,616 in 2014 down to 2,339 in 2016) that’s really not necessary.
The biggest concern with shortening the starter’s workload and transferring those innings to a reliever, especially one from a pool of seven pitchers, is how effective they will be despite pitching on short rest. But those concerns appear to be unfounded.
While uncommon, three days of rest appears to be ideal, but, last season, relief pitchers pitching on back-to-back days were almost as effective (.708 OPS against) and were more effective than those on one day (.718) or two days rest (.717). In fact, there was almost no noticeable difference between a pitcher’s strikeouts per nine innings or strikeout-to-walk ratio last season no matter how many days rest he got before his next appearance.
With rest not a pivotal factor, you really just want to guard against a starter who fails to reach the sixth inning before he sees a hitter for the third time. So long as you have one or two relievers capable of throwing three innings, you’re set in that department.
So, overall, here’s what the statistically perfect bullpen’s makeup would look like: Ideally, you’d have two relievers capable of taking over for a faulty starter, at least two pitchers who can handle high-leverage innings, two left-handed specialists who can get a left-handed slugger (or two) out and one jack-of-all trades. Now, how about we assign some current major leaguers to these roles?
The Perfect Bullpen
Now that we know what a perfect bullpen looks like, here are the relievers that would be perfectly suited for inclusion. Obviously money is not a factor here. We’re just compiling the best arms according to the principles mentioned above:
Aroldis Chapman, New York Yankees, LHP
There is no better fastball in the majors. Chapman’s fastball tops out at an MLB-record 105 mph, with 369 pitches registering in excess of 100 mph on the radar gun last regular season, 177 more than Mauricio Cabrera, who has broken the century mark the second most among MLB pitchers.
If a hitter does manage to get a piece of the ball, it rarely gets beyond the infield.
Dellin Betances, New York Yankees, RHP
Betances struck out over 15 batters per nine innings last season with his 3.08 ERA more a by-product of bad luck (.353 batting average against on balls in play) than skill (1.78 FIP).
Andrew Miller, Cleveland Indians, LHP
Miller, as a member of the New York Yankees, pitched multiple innings just two times, but after a trade sent him to Cleveland he was asked to pitch past one inning eight times during the regular season. He struck out 46 batters in 29 regular-season innings for the Indians, walking only two batters while holding opponents to a .139 batting average against. In the playoffs, Miller entered the game in the fifth inning three times and pitched multiple innings in four of the seven World Series games. He ended the postseason with a 1.40 ERA in 19 innings — the most innings ever pitched by a reliever in a postseason.
Brad Hand, San Diego Padres, LHP
Pitched a league-leading 82 games in 2016, holding left-handed batters to a .125 average against with an OPS that was 56 percent lower than the league average.
Brad Ziegler, Miami Marlins, RHP
Ziegler entered the game with an average leverage index of 2.16 last season — the second-highest among relievers — but saw that drop to 1.37 when he exited. In other words, Ziegler’s 63 percent groundball rate and command of the strike zone (11.7 percent swinging strikes) was instrumental in putting out fires.
Wade Davis, Chicago Cubs, RHP
Davis, a closer with a 95 mph fastball, has been one of the best at neutralizing the first two hitters in a lineup, holding them to a .183 average with a .513 OPS the past three seasons. If you’re looking for a default option to start games as the “leadoff pitcher,” Davis gets the nod.
Raisel Iglesias, Cincinnati Reds, RHP
Iglesias might not have the stamina to be a dependable starter, but he has three good pitches — a fastball, change-up and slider — with good command of the strike zone (3.2 strikeout-to-walk ratio) and should have no trouble going through the batting order in a game. He would be our long-reliever.