Unfortunately, if you are a major league front office employee, this is not a presentation of ground-breaking new research regarding the prediction of pitcher meltdowns that will save you innumerable frustrations. Rather, this post provides a summary of some of the basic factors that go into the decision to pull a starting pitcher. If you’re new to the game or are just starting to pay attention to sabermetrics, it’s likely that you haven’t really ever had a run down of the different decisions a manager needs to make when plotting out their mid- to late-inning choices.
The conventional wisdom is generally about two things, fatigue (usually in terms of pitch count) and effectiveness (usually in terms of a stat line or recent hitter performance). A pitcher will get yanked after 100-115 pitches unless they are absolutely dealing or a pitcher will get yanked if they’re getting hit around a lot. Over the first seven or eight innings, that’s typically the mindset of many. Of course, there’s the obnoxious “save situation” problem that arises in the ninth inning, but we’ll leave that for another day.
But in general, while fatigue and effectiveness are good variables, the decision to pull a starting pitcher is multi-dimensional. Let’s consider some of the factors in more depth.
First of all, the basic context of the game matters a great deal. If the game is of low importance (i.e. it’s September 25th and you’re 22 games back) or if the game is over (it’s 10-1 in the 6th inning), the decisions are less consequential. Either the game doesn’t matter or there is nothing you can do to win or lose the game. In these cases, the best decision is simply what is best for the players involved. Does the pitcher need work? Is he tired? However, when the game is important and still in doubt, there are a number of variables to consider.
Fatigue is a very important factor. Pitching tired can hinder a pitcher’s ability to get outs and it can be detrimental for his long term health and effectiveness. There isn’t hard evidence that each additional pitch leads to a specific current or future cost, but generally speaking if your pitcher is tired, it is a better idea to remove him than if he isn’t.
This isn’t a controversial idea, but how we measure fatigue is very much an open question. Pitches? Innings? Effort? Number of sliders? Batters faced? There are numerous ways to measure how tired a pitcher is, and there is no ironclad rule about when a pitcher starts to feel the negative effects. And each pitcher is different and can withstand different workloads. Plus, you have to consider in-game workload and overall season workload in tandem.
There is no fatigue rule, but watching out for it is an important part of determining when to pull a starter.
Times Through The Order
The Times Through The Order Penalty (TTOP) is something that is widely acknowledged, but only truly accepted by a few. The rule is this: each time a pitcher faces a lineup an additional time, they perform worse. Most baseball people believe this in general, but not many people appear to adhere to its implications.
One common challenge to the TTOP is the idea that pitchers can be “cruising,” or pitching very well such that the penalty will not apply that day. Imagine a pitcher who is shutting down a good lineup and is about to face them for the fourth time. The conventional wisdom says that pitcher will continue to cruise, but the TTOP suggests that the starter is going to perform worse. This manifests when a good starter is pitching well and about to face the lineup for a fourth time. Most managers would leave their starter in until trouble arrives, but the evidence indicates most relievers will perform better than the starter in this situation. Even though the starter isn’t “in trouble,” the smart move is likely to replace him.
This is an important consideration in close games. If the game is out of reach, it may be worthwhile to allow the starter to have the satisfaction of pitching deeper into games, or to save the pen, but when each run is very important, going to the better pitcher matters. And despite what we often think, a good pitcher the fourth time through the order is probably not better than many of the team’s relievers.
The basic rule, don’t let starters pitch to a lineup the fourth time through unless the game is out of reach or the starter is elite. Also, watch pitchers very carefully the third time through the order and have relievers ready to go.
We also have the specifics of the situation. The number of times a pitcher faces a lineup and fatigue are important considerations, but often times the specific decision should be governed by who you have in the pen and who the batters are. Having the platoon advantage late in games can be extremely valuable, so if you have a right-handed starter in the game with one right-handed batter followed by three left-handed batters due up, you may choose to leave the righty in the game for the first batter if you don’t have a good righty available, or if you know you’ll need him later.
There’s no perfect guide here, but you want to consider who you have in the bullpen and how many batters they will be able to face. A starter might not be as good the third or fourth time through the order, but depending on the game situation, you may decide to pull them early or late depending on how your bullpen is looking on a given night and organization of the other lineup.
In addition to these three main factors, there are some other miscellaneous things to consider. Or not consider, as it were. One of the big mistakes managers make is following along with the stat line too closely. It is entirely possible that pitchers “have it” on some days and don’t on others, but based on everything we know about sample size, simply knowing if a pitcher has given up zero runs or six runs in five innings is not sufficient information.
Maybe a manager has the ability to judge if a pitcher has his best stuff on particular day, but good results (or bad ones) do not guarantee future in-game results. Basically, when determining if your starter is the best option, judge them based on what you believe to be their true talent, adjusting for the factors above. Do not use the logic, “they’re cruising today!” just because they haven’t gotten hit around so far.
Another common trap is to think in terms of innings rather than outs. Trying to get a starter “through an inning” can lead to disastrous results. You have to accumulate 27 outs and the difference between a starter getting 17 or 18 is almost entirely psychological. If it’s time to pull the starter, pull the starter.
Also, if you’re in an NL park and you have a pitcher coming to the plate you generally want to err on the side of pinch hitting after the starter faces the lineup twice, but there is one basic rule to live by: if you’re planning to have the starter on a short leash in the next inning, it’s time to pinch hit. The gap between the pitcher and a pinch hitter at the plate is almost certainly larger than the gap between that pitcher and a reliever on the mound.
Ultimately, the basic structure of the decision has stood the test of time, but we also want to make sure that we are paying attention to the right aspects of effectiveness. Fatigue is fatigue, as long as you have a consistent way to evaluate it. When it comes to effectiveness, you want to base it on TTOP and the matchups available to you as a manager. If you have a good lefty starter about to face the other team’s best two righties for the fourth time, you almost always want to go to the bullpen in a reasonably close game.
Not every decision is simple. Sometimes you have to weigh a tired bullpen or a starter who matches up well against a given lineup against these basic rules. It’s especially tricky when you are tasked with managing an entire season. If a wild card game or in a playoff series, it’s easier to know when to pull the starter. But when you have to think about keeping everyone healthy and fresh, deciding to let the starter face another three batters because more of an art than a science.
This isn’t any kind of algorithm, but the general rule is pull the starter before he gets tired and before he sees a lineup a fourth time. There is often a push to give pitchers a chance to go deep into games or to demonstrate their toughness by facing additional hitters. It’s important to remember that this is not about toughness, but rather it’s about who gives the team the best chance to get outs. In today’s game, most relievers facing a batter for the first time are better than a tired starter the third and fourth time through. It can be hard to internalize when you’re watching a good starter pitch well, but as the game moves toward relievers, not leaving your starter in too long is an important consideration.
Neil Weinberg is the Site Educator at FanGraphs and can be found writing enthusiastically about the Detroit Tigers at New English D. Follow and interact with him on Twitter @NeilWeinberg44.