Insights on 1-Run Losses

This season in games through 5 August, the Diamondbacks lost 22 games by one run.

“…that [losing 1-run games] is the area that we need to fixate on…the areas we are going to fix.” — Mike Hazen

Why did Mike Hazen talk about 1-run losses? If the Diamondbacks could change 1-run losses into mostly wins, it would positively impact the win-loss record. The first step is to understand the underlying causes. Let’s see what data says about several possibilities.

Is the root cause newly called up players? In 1-run losses, veterans (players with at least 2 prior seasons in the Majors) accounted for 82.3% of plate appearances and 73.3% of innings pitched. That was a good balance between veterans and new players. Newly called up players were not an underlying cause. Data from Baseball Reference, games through 28 July.

Is the root cause playing elite teams? 12 of the 22 1-run losses were against elite teams. However, I cannot definitively answer the question, “Are 1-run losses to elite teams a sign of strong play by the Diamondbacks or a sign of weak play by the Diamondbacks?” Let’s move on.

Is the root cause a hangover effect from having lost the previous game? In 16 of the 22 1-run losses, the Diamondbacks lost the previous game. Did each loss degrade their competitive spirit? I’m not sure whether this means anything special about 1-run losses because this season the Diamondbacks lost twice as many games as they won. Although hangover effect could be a contributing cause, let’s move on.

Which had the biggest impact: starting pitching, the bullpen, or team offense?

The following table shows the 1-run losses. The biggest reason column shows my view of the biggest cause for each loss. In general, my expectations were 3 runs or more from the offense, 3 ERs or less from starters, and 2 ERs or less from the bullpen. Nine losses were attributed to the bullpen, eight losses were attributed to starting pitching, and five losses were attributed to lack of offense.

Diamondbacks’ games through 5 August. Data from Baseball Reference.

The waters were muddied because bullpen pitchers started some games due to unavailability of starting pitchers. Nevertheless, since 10 June, 6 of 10 losses were attributed to the bullpen.

Summary: The bullpen had a bigger impact than the rotation or the offense.

Were baserunning and defense contributing causes?

“...and yes baserunning has been a big part of that, our defense has been a big piece of that….Those are areas we are focused on fixing.” — Mike Hazen

Mike Hazen said baserunning and defense were a big part of the cause for 1-run losses. Let’s look at them.

The following graph shows the 13 players with at least 100 PAs. It shows baserunning prowess (their extra bases taken plus stolen bases per PA) and their Defensive Runs Saved (DRS). Note: DRS was only for each players’ primary position played except for P. Smith, Cabrera, Rojas, and Varsho. Those 4 players were considered utility players and their DRS’s were summed for all positions they played.

Diamondbacks’ games through 5 August. Data from Baseball Reference and The Fielding Bible.

From this graph we see Ahmed, Calhoun, and Varsho as excellent baserunners and excellent defenders. The other players have room for improvement in at least one of the two areas.

Let’s look at players who could improve most (Ketel Marte, Josh Reddick, and Pavin Smith). First, lets me emphasize that despite their potential improvement these are excellent players and the team wins more games when they play. In games through 28 July, Marte and Reddick accounted for twice as many PAs in 1-run losses as in all games (the two players totaled of 12.0% of PAs in 1-run losses vs 7.6% of PAs in all games). If they improved their baserunning and defense, these two players could have a significant impact because they play more frequently in 1-run losses. And Pavin Smith had 10.2% of the PAs in 1-run losses, almost as many PAs as Marte plus Reddick. If Smith improved he could have an impact.

Summary: Baserunning and defensive improvements could change some 1-run losses into wins.

Was the bullpen a root cause?

The following graph shows eight pitchers who pitched a total of at least 5 innings in relief in 1-run losses. It shows their ERAs and total inning pitched in those games. Most of the pitchers had ERAs that were within a relatively narrow range (3.86 to 4.5), except for Mantiply, Peacock and Martin. Mantiply has an exceptionally low ERA, but a small sample size of 5.1 innings. Peacock and Martin had high ERA’s but again small sample sizes.

Diamondbacks’ games through 5 August. Data from Baseball Reference.

Before Clarke allowed 3 earned runs on 5 August, he performed very well in 1-run losses. Including 5 August, he did not allow any earned runs in 8 of his 11 1-run losses. That’s the kind of results that are great for a reliever.

For the season, the bullpen’s negative 7.5 Wins Above Average ranked last in the Majors. However, the Diamondbacks play most of their games against teams in the NL West.

For the season through 6 August, let’s compare the bullpen’s ERA to other teams in the NL West.

• 2.91 ERA, Padres
• 3.26 ERA, Giants
• 3.64 ERA, Dodgers
• 5.39 ERA, Diamondbacks
• 5.64 ERA, Rockies

The Diamondbacks and Rockies bullpens have much higher ERAs than the other teams in the NL West. Except for Mantiply, during 1-run losses all the bullpen pitchers with at least 5 innings pitched had ERAs that were higher than average for the Padres, Giants, and Dodgers.

Summary: The bullpen was a root cause of 1-run losses.