Every baseball season is a little different, but some elements are more consistent than others. One of those elements is the win rate with a lead after five innings.
Making a First Five Innings bet as opposed to a full-game wager is always a major decision. Many bettors want to avoid bullpens, but teams across baseball are pretty consistent in their ability to hold a lead entering the sixth inning. The MLB average win rate is typically around 83%.
This season, however, is different, and that’s the subject of this week’s Regression Report.
For this data set, I’ll look at the last five full seasons compared to this season. The specialization of the game has only increased in that span, as we’re seeing fewer starter innings, more relief innings and managers being more aggressive in taking starters out after five innings to avoid the third-time-through-the-order penalty (statistics through Sunday’s games).
Plate appearances versus pitcher for the third time
We’re on pace to see a similar number to 2021, which was an odd season coming off of the shortened 2020 schedule.
Even though managers have avoided the third-time-through-the-order penalty at a higher rate over the last few years, the win rate with a lead after five innings has remained pretty consistent, at least up until this season. That adds fuel to the fire that we’re going to see more blown saves and bullpen mishaps as the season goes along.
Winning percentage with a lead after five innings
Is the win rate going to decline? I think so. The increased offensive environment and starters being stretched out a little more will not only reduce reliever effectiveness, but it will also increase the frequency in which starting pitchers go into the sixth or later and leave messes for relievers.
We’ve already seen a decrease in reliever effectiveness from April to May this season.
Monthly reliever statistics in 2022
April: 3.48 ERA, 3.69 FIP, 24.1% K%
May: 4.08 ERA, 3.95 FIP, 22.9% K%
Reliever attrition is a real thing. Relief pitching is a remarkably difficult role, especially with the strain it puts on the arm. Managers rely heavily on their most-trusted arms, which leads to injuries and bad performances as workloads increase. Plus, hitters around the league get more familiar with relievers and scouting reports get stronger as the season goes along.
Some teams are going to be more affected than others in terms of holding on to leads.
Win rates of 90% or higher with a lead after five innings
— Cardinals: 23-0 (1.000)
— Guardians: 11-0 (1.000)
— Astros: 28-1 (.966)
— Giants: 22-1 (.957)
— Mariners: 16-1 (.941)
— Marlins: 15-1 (.938)
— Dodgers: 28-2 (.933)
— Rays: 21-2 (.913)
— Orioles: 10-1 (.909)
Win rates of 80% or lower with a lead after five innings
— Royals: 10-4 (.714)
— Pirates: 11-3 (.786)
— Red Sox: 15-4 (.789)
A good shortcut for baseball handicapping is to look for extreme outliers to regress toward the mean. The Cardinals and Guardians are not going to maintain perfect records with a lead after five innings. The Astros and Dodgers are going to blow a few games here and there. Knowing when those teams will blow leads is impossible, but outlier performances, especially in close games, can create inflated perception and pricier lines.
Looking through the data and analyzing the state of this baseball season, it’s my belief that bullpens are going to create more headaches for bettors moving forward. That is not a suggestion to only bet First Fives, but rather a nudge to be even more vigilant about bullpen usage and the relievers available in any given game.