Scouting The At-Bat: Rex Brothers Vs. Brian Bogusevic

In baseball, there is a ton of data available before every pitch. Tendencies can be shown, splits analyzed, but it all comes down to an elaborate chess game between the pitcher and the hitter in that moment. This is something I'm thinking of doing periodically, looking at one particular at-bat through a scouting lens to see what led up to it and try to explain what happened.

First up, we've got the climactic conclusion of Sunday's affair, as Brian Bogusevic, a lefty, laced a single through the right side against Rex Brothers, also a lefty. This was Bogey's first at-bat against a lefty in seemingly forever, which was notable in itself.

Let's talk about what Bogusevic probably expected from Brothers coming into the at-bat.

Brothers is a hard-throwing lefty who primarily works off a four-seam fastball and a slider. He uses the fastball nearly 75 percent of the time and mixes in the slider sparingly. His fastball averaged 95 MPH last season, according to FanGraphs, with his slider clocking in about nine MPH slower than that.

In 40 relief innings last season, Brothers saw both of his two main pitches used very effectively and had positive linear weights. However, we're not looking for an overview here. We want to know which of his plus offerings he might throw to Bogey. Let's get to that after the jump...

Brothers didn't really change up his style when throwing to left-handers last season. He still threw about 70 percent fastballs and mixed in sliders about 30 percent of the time. His slider was slightly less effective to lefties, as he only got a 20 percent whiff rate on it. Against righties, that number jumps to 29 percent.

Against left-handers, Brothers throws his fastball pretty much all over the zone, but tends to stay away from the inside part of the plate. That may be because his fastball gets pretty good downward movement, and that way he can pick up more ground balls. It also could be because he throws 96-freaking-MPH and can just blow it by hitters.

At any rate, Bogusevic probably shouldn't have expected to see a heater in on his hands from Brothers. He should, however, have been expecting a fastball.

If we look at Brothers' tendencies in first pitch situations, he threw nearly 80 percent fastballs. That's partly because his slider wasn't a very effective strike for him in 0-0 situations, as he threw it for a strike just about 50 percent of the time and saw the batter swing at it less than a quarter of the time.

We're dealing with smaller and smaller sample sizes here, people, but bear with me. Of those 13 first-pitch sliders Brothers threw, most of them were up in the zone. Some were very high, which suggests either he had trouble throwing the pitch or problems classifying them with Pitch F/X.

However, none of his sliders to lefties on 0-0 counts were down and in last season. That's the last place Bogey should have been expecting the ball.

On the other hand, Brothers knows that of the handful of at-bats against lefties that Bogey got last season, he saw a slider the most. That'd be 16 sliders, in fact, compared to 15 fastballs and 12 two-seamers. Not exactly a huge sample here either.

He also swung quite a bit at those sliders, as much as at any other pitch, but whiffed on it about the same as he did the fastballs. The problem with Bogey is that he put sliders in play almost 20 percent of the time he saw them from a lefty, compared to just 6 percent in play on four-seam fastballs.

Further, if we look at his swing pattern (in this ridiculously small sample), we'll see that Bogey saw four sliders on the first pitch of at-bats last season, but swung at only one. So, there's a good chance Brothers could sneak a slider in for a quick strike and get ahead in the count without Bogey swinging.

Okay, so now we know that Brothers is likely to throw Bogey a four-seam fastball on his first pitch. That's what Brothers tends to throw and that's probably what Bogey was looking for in that situation.

We also know that Bogusevic has a very small track record against left-handers, but that he's been known to watch sliders more than other pitches.

What happened?

Brothers started Bogey out with a slider down and in. It was a very good pitch, just look at the location here:

It was the pitch he wanted to make in a great location. Bogusevic just hit it well and pulled it through the right side for the game-winning RBI.

There's no way scouting could have figured out that Brothers would throw a slider in that particular count. We have some vague notion of tendencies, but more likely is that Bogusevic knew Brothers' fastball was his real weapon and was on guard for that. When he saw the slider, he committed to swinging and came up with the base knock.

After the game, Bogey admitted as much, saying, essentially, that Brothers is a tough out and if he's going to give him a pitch (implied non-fastball), then it's his job to take advantage of that.

Research for this article done through FanGraphs, Brooks Baseball and Texas Leaguers.