2019 MLB Season Betting Preview: Good Defensive Teams Tend to Beat Their Win Total

In 2018, MLB teams who exceeded Las Vegas's season win total projection also performed better defensively, both in Defensive Runs Saved (DRS), and Defensive Runs Above Average (DEF) than the teams who went under their season win totals.

In fact, 73% of the teams that went over their win totals showed positive metrics in either DRS or DEF; while 63% of the teams who went under their win totals showed negative markers in either DRS or DEF.

Here are the defensive averages per team from the 2018 season, grouped by the teams who went Over and Under their win totals:

• 2018 Over: +14 DRS; +6.5 DEF
• 2018 Under: +6 DRS; -4.3 DEF

The Phillies, and Exceptions at the Extremes

This trend didn't necessarily hold true at the extremes.

The Philadelphia Phillies surpassed all projections in 2018 despite finishing 30th in DRS (-146) and 28th in DEF (-45.6), while the Los Angeles Angels fell two wins shy of their total while finishing 6th in DRS (+49) and 1st in DEF (+50.2).

With nine to ten runs roughly equivalent to one win, the Phillies likely would have won the NL East if they had performed as an average defensive team last season.

They addressed some of those concerns during this offseason, by trading for Jean Segura (+5 DRS in 2018 at shortstop, 10th in MLB) and signing Andrew McCutchen (+2 DRS in 2018 in right field,  12th in MLB).

Bryce Harper's fit on defense is a different story. Harper claims that playing in center field in Washington hurt his defensive metrics last season, but don't let those comments fool you; he earned -16 DRS in right field alone.

Combining Harper's defensive metrics and offensive output, it appears as though he has alternated between healthy and unhealthy campaigns over the past four years: 2018 (-26 DRS, .889 OPS); 2017 (+4 DRS, 1.008 OPS); 2016 (-3 DRS; .814 OPS); 2015 (+9 DRS, 1.109 OPS – MVP season).

If Harper can return to playing scratch defense in a corner, it will be a massive upgrade for the Phillies. Rhys Hoskins (-24 DRS) was nine runs worse than any other left fielder in 2018, while Nick Williams (-15 DRS) was the third-worst right fielder. The enigmatic Odubel Herrera (-9 DRS) also ranked 17th amongst 20 qualified Center Fielders.

With a natural shortstop in tow to finally replace slick defender Freddy Galvis, Rhys Hoskins manning his natural position, and two all-star corner outfielders, the Phillies regular lineup should be much more sound than last season's version, on both sides of the ball.

That being said, they can still make a significant upgrade at the hot corner. Maikel Franco (-22 DRS) has been a bottom-four defensive third baseman over the past three seasons.

(Want a fun fact? The Yankees Miguel Andujar (-25 DRS) heads up that pack after just one season. If Matt Chapman is David Dunn, then Andujar is Elijah Price.)

Upshot

Defense is often the most overlooked aspect of baseball analysis. In the aggregate, the quality of a team's defensive metrics might correlate to the likelihood of that team going over or under their season win projections.

Team defense is also something that an MLB club can improve upon in a much more cost effective way than merely acquiring better pitchers or better known offensive contributors.