Numbers are fun. Specifically in baseball, numbers are everywhere. In the Statcast era we can quantify everything. The speed of the ball, the speed of the bat, the speed of the player, distances balls are hit, etc. Everything is quantifiable. One thing that is easy to quantify is how many times a player steals a base and how many times they are caught stealing. Right? One thing that isn’t easy to quantify is the impact that those stolen bases have on offensive performance.
I’m going to give this a fairly simple answer. If a player hits a double, they are credited with two total bases towards their SLG%. If a player hits a single, they are credited with one. If a player walks, they get credit toward their OBP. If they ground out, their OBP will decrease. Stolen bases aren’t that much different. If Whit Merrifield singles, and then steals 2nd base, he has essentially hit a double, yeah? He’s on second base by his own hand. He didn’t need any help to get there. But if he’s caught stealing, he may as well have not even singled in the first place. Like Brad Pitt said in Moneyball, “No, I pay you to get on first. Not get thrown out at second.”
So here’s what we’re going to do. I’m going to go through the league leaders in both stolen bases and caught stealing and add their totals to their slash line. My goal is to get a better idea of how guys like Whit Merrifield and Dee Gordon will compare to sluggers like Sal Perez and Nelson Cruz when stolen bases are factored into the commonly used slash line. So for every stolen base that Whit Merrifield has this season, we’ll add one base to his SLG% total. For every time he was caught stealing, we’re going to remove a hit from his OBP. I’m also going to add intentional walks to my adjusted OBP because it’s ridiculous that they aren’t already included. Make sense? Let’s run some numbers.
- Real slash line: .281/.297/.449/.746
- Adjusted slash line: .247/.264/.539/.803
Mondesi has hit for an impressive amount of power as it is, but when you add in eight stolen bases in 26 games and it’s even more impressive. He doesn’t get on base to get thrown out 27% of the time, but the tools have been explosive so far and Mondesi’s speed/power combo could create a huge adjusted slash line in the future.
- Real slash line: .297/.368/.418/.786
- Adjusted slash line: .285/.358/.474/.832
As you can see, Whit Merrifield’s stolen bases increase his adjust SLG% by an impressive 56 points. His OBP takes a small hit because he’s been caught stealing five times, but his increase in SLG% sends his OPS up 46 points. There are only 47 qualified hitters in baseball with an OPS greater than .832 this season. Whit has hit for less power in 2018 than he did in 2017, but his ability to move up a base on his own evens out for the extra bases he hasn’t hit.
Khalil Lee (A+)
- Real slash line: .270/.402/.406/.808
- Adjusted slash line: .258/.392/.463/.855
Another guy who has seen his power decline a bit in 2018, Khalil Lee has stolen enough bases this season to give his adjusted SLG% a nice boost.
Nick Heath (A+)
- Real slash line: .276/.391/.354/.745
- Adjusted slash line: .229/.345/.505/.850
The poster boy for this experiment, Nick Heath doesn’t hit for much power to speak of. He’s very much a slash-and-dash type of hitter that relies on a high BABIP and crazy BB% to be on base at an elite level. He lets his legs take over from there. A potential 75-grade runner, Heath’s speed is no joke. He stole 29 bases in 53 games in the Carolina League this season, but was also caught 9 times. Those nine stolen bases cost his team a base runner, but those 29 stolen bases also gave his team a runner in scoring position without having to sacrifice an out. Nick Heath was sort of the reason for this experiment, and the crazy difference between his slash lines is the reason why.
- Real slash line: .294/.404/.626/1.030
- Adjusted slash line: .286/.417/.688/1.105
Jose Ramirez is ridiculous. How can that real slash line even be real? Goodness. He got a huge boost in OBP despite being caught stealing three times because he’s been intentionally walked NINE TIMES this season. His 24 stolen bases are tied for third in the MLB this season and his three caught stealings are by far the fewest among SB league leaders. This dude is insane.
- Real slash line: .268/.340/.445/.785
- Adjusted slash line: .239/.315/.478/.793
As you can see, Rougned Odor is on the bad end of this adjusted slash line. He’s stolen nine bases this season, but he’s been thrown out eight times. His OPS still goes up because technically, he’s in the positive column, but he’s been thrown out far too often to continue running at this pace.
- Real slash line: .291/.309/.353/.662
- Adjusted slash line: .271/.284/.416/.700
It’s been a rough year for Gordon offensively, and the eight caught stealings don’t help. His already low .309 OBP is even worse when you consider that he’s been removed from the base paths eight times. The 25 stolen bases are nice, and aid a poor SLG%, but the overall offensive production from Gordon this season is not what it once was.
There’s seven examples for you for an adjusted slash line. As you can tell, players who steal a lot of bases will see a nice little increase in their adjusted SLG%, and players who get thrown out a lot will see disappointing decreases in their OBP, as they should. Getting caught stealing is just like having never been on base at all, just like stealing a base is just like having hit a double in the first place. Hopefully there will be a more scientific way for us to calculate SB into general offensive performance in the near future.