Troy Tulowitzki has been on fire since the month of September began. On Friday night, Tulowitzki homered for the 12th time in just 16 games this month. He has tied Toronto Blue Jays slugger Jose Bautista for the most home runs by a player in any month this season (Bautista homered 12 times in August and May this season). According to the Elias Sports Bureau, he is the first player in major league history to hit 12 or more homers over the first 17 days of September.
He has plenty of time to move up into the list of most home runs in the final month-plus of games in major league history. Albert Belle owns the record for the most home runs in September/October games; he hit a whopping 17 in 1995 for the Cleveland Indians. Right now, Tulowitzki's rate of 5.42 at-bats per home runs in these games is currently bested only by Barry Bonds during his record-breaking 2001 season.
AB per HR in September/October Games
MLB History, Minimum 50 PA
Entering this season, Tulowitzki had hit a total of 18 homers in September/October games. It's certainly conceivable that he could pass that total in the 15 remaining games the Colorado Rockies have left on their schedule. This infusion of power has raised his career slugging percentage in the final month of the season to .579, his highest career slugging percentage of any the six months played during the regular season.
Why has he been so successful? He's been taking advantage of fastballs and curveballs. This month, Tulowitzki has a .485 batting average on at-bats that end on the fastball, well above the league average of .285. When at-bats end on a curveball, Tulowitzki has a .375 average, also well above the league average of .230.
It might not be a surprise, but it's still worth noting that left-handed pitchers have struggled against him as well this month. He has a slugging percentage of 1.611 in 18 at-bats vs lefties. Right-handers haven't exactly had their way with him, either. Tulowitzki has a .745 slugging percentage against them, which is more than 300 percentage points higher than the league average.
So how do you get him out? Throw him sliders and changeups. According to Inside Edge, he has yet to get a hit in an at-bat that ends on a changeup (0-for-7) this month. And he's been barely above league average on at-bats that end on sliders, sporting a .235 average (league average is .225).
But then again, maybe it's just a September to remember for Tulowitzki and the Rockies.