How do the teams compare?
Which of these two teams had the better fielding, offense, and starting pitchers depends how you look at it. On the other hand, the bullpen was not ambiguous. The Mariners bullpen was clearly better. Details follow.
Fielding. This season through 29 August, the data is suggestive but not entirely one-sided. The Mariners were better in Defensive Runs Saved (negative 5 vs negative 10), Unearned Runs (49 vs 75), and percentage of unearned runs (8% vs 10%). On the other side of the coin, the Diamondbacks were better in Ultimate Zone Rating (UZR of negative 4.4 vs negative 9.6), and FanGraphs’ Defense (Def of negative 0.4 vs negative 11.6). Although Def added a positional adjustment to UZR, the data showed different positional adjustments for each team.
On 30 August, Diamondback fielding errors cost runs in a loss against the Padres. During the game thread, Jim McLennan commented that the reluctance of the scorer to charge more errors was inexplicable. Jack Sommers replied that at least DRS assigns negative values for obvious misplays and failures to record outs.
“…But the simple things of backing up bases, throwing to the right base, getting your feet set up, driving throws to cutoff men, driving throws to your teammates no matter where they are, that’s something we do well because we practice it a lot. When we get sloppy, I think it’s [that we need] more focus and effort and that’s when I have to step in.” Torey Lovullo
Offense. This season through 29 August, the teams’ offenses were closely matched. The Mariners were better in Wins Above Average (WAA of negative 6.2 vs negative 7.6). The Diamondbacks were better in fWAR (10.3 vs 8.5).
Let’s broaden the comparison by looking at runs scored and runs allowed. Despite their winning record, the Mariners are known for blowout losses. Therefore, just comparing averages would not be insightful. Let’s compare ten recent games through 29 August.
Let’s look at how many games each team deserved to lose. Let’s assume that ‘deserving to lose’ means scoring 2 runs or less, while allowing the other team to score 7 runs or more. Each team had one of those games.
Next, let’s look at how many games each team deserved to win. Let’s assume that ‘deserving to win’ means scoring 3 or more runs while allowing 6 or less runs. The Mariners had five of those games compared to three for the Diamondbacks. The Mariners have an edge, but it’s not so large that they could feel confident about winning a three game series.
Starting pitching. The Mariners were better in fWAR (5.9 vs 5.3). The Diamondbacks were better in Wins Above Average (WAA of negative 0.5 vs negative 1.2). Those statistics are less useful because they are spread over 16 starting pitchers for the Diamondbacks and 15 starting pitchers for the Mariners.
Perhaps a better comparison would look at recent starters, such as who started the ten games through 30 August. In those games, each team had a total of 5 starters. Let’s look at their season ERAs in ranked order:
- 2.93 Tyler Gilbert vs 3.18 Tyler Anderson
- 4.28 Taylor Widener vs 3.52 Chris Flexen
- 4.32 Zac Gallen vs 4.02 Marco Gonzalez
- 4.37 Madison Bumgarner vs 4.33 Yusei Kikuchi
- 4.91 Humberto Mejia vs 5.44 Logan Gilbert
The Bullpen. The Mariners have a much better bullpen. Their fWAR was better (5.8 vs negative 1.1). Their Wins Above Average was better (WAA of negative 0.9 vs negative 9.8). On 29 August, for those statistics the Diamondbacks bullpen ranked last in the Majors.
Note that all pitchers were TBA on 1 September. Actual matchups could vary.
Friday, Tyler Anderson (3.18 ERA with the Mariners) vs Madison Bumgarner (4.37 ERA)
The Mariners acquired Tyler Anderson by trade on 28 July. His ERA improved from 4.35 in 18 starts with the Pirates to 3.18 in 6 starts with the Mariners. This SO/BB ratio improved from 3.44 to 8.33.
“I had no feel, no idea where the ball was going. It was really bad. That’s as bad a game as I’ve thrown in a long time, and I’m surprised it wasn’t a lot worse.” – Madison Bumgarner
After the All-Star break, five of Bumgarner’s nine starts were great (game scores above 60). In his last start his game score was the worst since before the All-Star break. He walked four batters, tying his season high. That game had an upside - he allowed zero homers. I’m confident he will bounce back in this game.
Saturday, Marco Gonzalez (4.02 ERA) vs TBA
The Mariners won the last four games which Marco Gonzalez started, including a complete game with 1 earned run against the Rangers.
Although he is in the bullpen, Taylor Widener is back. In his last four starts, Taylor Widener was very consistent. He completed 5 innings, allowed 1 or 2 earned runs on an average of 3 hits per game. His ERA in those games was 2.70. Whoever starts this game can feel good that Taylor Widener is in the bullpen.
Sunday, Chris Flexen (3.52 ERA) vs Tyler Gilbert (3.37 ERA as a starter)
Chris Flexen is an ace. This season, the Mariners won 17 of the 25 games he started. In one of the losses, Flexen allowed 1 run in 6 innings, and the Mariners lost 0-1. He faced Greinke who pitched 8 innings with zero earned runs. I’m happy to know Greinke continues to pitch remarkable games.
This season, the Diamondbacks won 3 of the 7 games Tyler Gilbert started. They could have won his last start against the Padres. In addition to the two unearned runs, my view is that sloppy defense was responsible for one of the earned runs charged to Tyler Gilbert. In this game, Tyler Gilbert could exceed expectations.