Daniel Norris' fastball is the key to his future

While he struggled on Sunday night in Game 2 of the NLCS, Jake Arrieta has enjoyed a pitching renaissance since joining the Chicago Cubs in 2013. He has a 2.26 ERA in 67 regular season starts with the Cubs, including a 1.77 ERA in 229 innings this year. While his slider gets a lot of the credit for Arrieta's turnaround, those closest to him have cited an improvement in fastball command as the main reason why Arrieta has gone from bust to ace, and potentially the NL Cy Young winner in 2015.

Luckily for the Detroit Tigers, top prospect Daniel Norris does not appear to be going through the same growing pains Arrieta did. Norris held opponents to a 3.68 ERA and 1.01 WHIP in eight starts down the stretch, and a 1.76 ERA in his last four outings of the season. He only struck out 27 batters in 36 innings with the Tigers, but rarely showed any of the command issues that plagued him throughout his time in the minor leagues. He only walked seven batters in eight starts, and three of those came in one outing.

Armed with a standard four-pitch arsenal, Norris has garnered praise for his fastball, which sits anywhere from 92 to 95 miles per hour, and a biting slider. Baseball Prospectus noted the late life on Norris' fastball when they named him the Blue Jays' No. 2 prospect heading into the 2015 season. Minor League Ball labeled his fastball, slider, and curveball as potential plus pitches, while just about everyone pointed out the aforementioned command concerns.

Let's focus in on the fastball, a pitch Norris threw nearly 60 percent of the time after being acquired by the Tigers in July. He largely worked up in the strike zone and to his glove side, meaning the ball came in on right-handed hitters and away to lefties.

This may be due to Norris' position when on the mound. In most of his starts, Norris worked from the third base side of the rubber, a position left-handed pitchers stand in to help them work inside against righties.

Norris held opponents to a .222 batting average on the fastball in 80 at-bats, but his .432 slugging percentage allowed showed that it is still a work in progress. He induced a relatively impressive 6.48 swinging strike percentage on the fastball, which jumped to 8.5 percent if you exclude those classified as 'sinkers' by Brooks Baseball. As you might expect, most of those whiffs came on fastballs up in the strike zone.

When opponents put the fastball in play, they beat it into the ground more often than usual. They also hit pop-ups at a 12 percent rate, a tick above the league average of 10.1 percent. While both of these trends may just be a fluke -- we are talking about a 36 inning sample, after all -- there is reason to believe the weak pop-up contact may continue.

MLB Advanced Media has not released much of its Statcast data, but the snippets we do have show that Norris' fastball has an average spin rate of 2,382 rpm, well above the league average rate of 2,212 rpm. Higher spin rates generally lead to higher swinging strike and pop-up rates, two outcomes that lead to easy outs.

The high spin rate on Norris' fastball also leads to less vertical drop as the pitch travels towards home plate, which many construe as a "rising" effect. With so many hitters relying on an uppercut swing to counteract MLB's low strike zone, locating the fastball upstairs -- especially one with a lot of backspin on it -- could lead to a lot of easy outs.

Despite a shorter stride than most pitchers -- a factor that helps improve perceived velocity because of how quickly the ball gets to home plate -- Norris has been able to fool hitters with some combination of his high fastball spin rate and deceptive delivery. He has only gotten into trouble when leaving the ball over the plate, which can be said for any pitcher in baseball. As Norris improves his command, both down and up in the strike zone, his fastball should be a true weapon, helping him to set up his sharp secondary pitches and give opposing hitters even more fits than he already has.

Catherine's grade: B+

Norris was the pride and joy of the Price trade. He's lived up to the billing, putting forth a solid record in his time with the Tigers. He landed on the DL on Aug. 19 with a right oblique injury that was initially thought to be season-ending. He was back in less than a month and tossed five innings of perfect ball. He nearly did the same thing on the last day of the season. But being on a pitch count since coming back from injury, Norris was unable to showcase his true potential and it limited what the Tigers could do with him.

Expectations for 2016

While the Tigers have vowed to acquire two starting pitchers this winter, one has to assume that Norris' spot in the rotation is safe. He finished the season with a flourish, tossing a pair of scoreless outings against the White Sox and allowing just three earned runs in all of September. He struggled at times, but also showed flashes of his lofty potential, including the lively fastball detailed above. The Tigers may look to limit his innings, but after throwing 150 innings across two levels in 2015, it wouldn't be a huge surprise to push the 180-inning barrier if all goes well. There will be growing pains, but from what we have seen from Norris so far, they will be worth it.