How Good Does the Offense Need to be for Teams Emphasizing Pitching and Defense?

Recent versions of the Cardinals have emphasized pitching and defense with some success. They led baseball in Defensive Runs Saved this season, came in a solid 4th last year, and have finished in the top 10 in five of the last eight seasons. I know ERA is a caveman stat in the modern baseball world, but they’ve been top 10 in ERA in seven of the last nine seasons. If you’d rather use FIP-minus, they’ve been top 10 five times in the last nine seasons. A lot of that is because of good defense- pitching and glovework go hand in hand. Given that Busch Stadium plays as a pitcher’s park, it makes sense to lean into an advantage the Cardinals already have. They’ve done so effectively. However, pitching and defense are only part of the equation for a team’s overall quality. Even great pitching and defense can only lend so much support in absolving the sins of a bad offense. Today, let’s look at how good an offense has to be to do its part in supporting good pitching and defense.

First, we need parameters. I’ll collect every team from 1990 to 2019, and assign their ordinal rank in FIP-minus and Fangraphs’ DEF (Defensive Runs Above Average). I know ordinal rank isn’t ideal- there’s not a ton of difference sometimes between the 15th and 16th team, for example- but it’ll work to give us a quick snapshot. We want all teams that finished in the top 10 in the league in both of those measures. There are 117 teams that accomplished this feat. Cardinal teams to have done so include the 1990, 1997, 2004, 2009, 2015, and 2017 editions, if it helps give you an idea of what we’re working with.

The collective pythagorean record for those 117 teams is a .562 winning percentage, or 91 wins. More than 2/3rds of those teams were above a .550 pythagorean winning percentage. If you finish in the top 10 in both FIP-minus and DEF, there’s a very good chance you’ll make the playoffs. I also further carved the quality down by looking only at top 5 teams in both categories, but the needle doesn’t move much. Those 38 qualifying teams had a collective .570 winning percentage. It’s worth 1.3 more wins per year, which is significant but doesn’t dampen the importance of merely finishing in the top 10 instead of top 5.

Since we know these teams have above average pitching and defense, we can now measure the impact of their offense. We’ll do that with a simple scatterplot of their team wRC+ (non-pitchers) and their pythagorean record. Ideally, the higher the wRC+, the higher the pythagorean record. Here’s how that looks:

That’s not a perfect relationship, but a .50126 R-squared is respectable enough. Generally speaking for pitching and defense teams, every extra point of wRC+ is worth 7/10ths of a win. A team with a 100 non-pitcher wRC+ would expect a pythagorean winning percentage of .548, or 88.8 wins. Or at least, 50% of a .548 pythagorean expected performance could be explained by their wRC+. Push it up to 104 and it’s just under a 92-win pace. A team wRC+ of 110 spits out over 96 pythagorean wins.

To answer our question from earlier, simply being an average team at the plate (100 wRC+) would get most teams to the playoffs if they have top-10 quality pitching and defense, particularly in the two wild card era. That’s a decent goal with the hope for more.

This says nothing of how high a team’s pitching and defense falls, ordinally, in DEF and FIP-minus. Simply making it as a top-10 team in those categories affords them leeway on offense that other teams don’t have. The better the pitching and defense, the more of a cushion a team has with their offense. For these quick and dirty purposes, I’m not going to dig further into it but you get the idea.

This would all seem like good news for the Cardinals entering 2021. In theory, simply bumping their wRC+ from this year’s 93 back up to last year’s 100 would represent a massive swing of 5+ wins. It’s a low bar. The problem is that these numbers are predicated on the Cardinals being a top-10 team in both FIP-minus and DEF. They’ve satisfied the defensive component in both 2019 and 2020, but their FIP-minus has lagged. They were 14th last year and 20th this year. Admittedly, this year was odd for many reasons, from small samples to a Covid-depleted bullpen to a grueling spree of doubleheaders that taxed the entire pitching staff. It’s understandable if you don’t think they were truly as bad as 20th this year. Still, even last year, they were 14th, which still doesn’t satisfy our requirement.

The point of this article was to demonstrate that, with even an average or slightly above offense, a team strong on pitching and defense can be playoff quality. The larger point is that if the Cardinals are going to be that kind of team, the pitching needs to hold up more of their end of the bargain, and the offense still needs to make strides.