In February, I wrote an article asking what it would take for Royals shortstop Bobby Witt Jr. to make the jump to being an 8-to-10 WAR player.

Well, it’s August 15 and Witt’s at 7.9 WAR per Baseball-Reference and 8.3 WAR via FanGraphs. We suspect he’s not going back below those numbers, so let’s look into one aspect of how he got there – maybe not one you think about.

Defensive Runs Saved can be used to measure fielder performance in any number of ways, including against a specific player.

Opposing defenses have -16 Defensive Runs Saved on the balls hit by Bobby Witt this season. That’s the worst total against any player in the majors.

This is not to discredit Witt so much as to show that he puts a lot of pressure on opposing defenses with his speed.

For example, this ground ball hit to Mariners shortstop J.P. Crawford has a 92% out probability but Witt beats it out. This one to Dodgers second baseman Gavin Lux has an 87% out probability but again Witt beats the throw to the base. And here’s a comebacker that Casey Mize muffed, a play that had a 100% out probability at the time. But not anymore.

Defensive Runs Saved incorporates a player’s speed within its out probability calculations by placing the players into five different speed groupings based on a combination of stats (home-to-first time being the primary one with a Bill James- devised formula utilized if there’s not enough sample of home-to-first times). The top grouping encompasses the fastest 10% of MLB players.

Witt is in the fastest grouping and at the very top of it. He’s in the Top 10 in average home-to-first time and has the fastest sprint speed. Witt’s now hitting .422 on ground balls this season with as many infield hits (15) as he had in 2023. That batting average ranks second to Cody Bellinger’s .438.

Similarly, if you miss a fly ball against Witt, he’s going to burn you. He’ll hurt your Runs Saved and boost his slugging percentage. This ball had a 93% out probability for Rangers center fielder Leody Taveras but he missed it, it went over his head, and Witt wound up with a triple. This one had a 71% out probability for Tigers right fielder Kerry Carpenter. But it too ended up a Witt triple. Witt is tied for second in MLB with 11 triples this season, 5 of them coming on balls that had an out probability of at least 50% for one fielder.

You might think that Witt benefited from opposing defenses in his first two seasons in the majors too. He did in 2022 when defenses had -18 Runs Saved against him, but last season they saved 4 runs on his batted balls.

As you’d expect, the players against whom defenses have the most trouble per Runs Saved are some of the fastest players in the sport. Here’s this year’s leaderboard through Wednesday.

Fewest Defensive Runs Saved By A Defense

On Player’s Batted Balls (2024)