Stat Analysis Tells a (Trevor) Story

Through 13 games of the 2016 regular season, Colorado Rockies shortstop Trevor Story has put up a .309/.339/.855 stat line, good for a 1.194 OPS. Extended out over a full 162-game season, and Story projects to hit 100 Home Runs (99.7 to be exact), and drive in 174 runs. Continuing this production would surely be thrilling, but not only is that unlikely, rather, it is impossible, even if Story spends his days and nights hitting in Coors Field, Colorado.

*Note – if you do not care about how I got to the final projections, then the following paragraphs will be irrelevant to you. If that is the case, then feel free to scroll to the bottom where you will find Story’s season projections in Bold.

So, I am going to try projecting an actual Trevor Story stat line for the rest of the season. All stats used have been gathered from FanGraphs, which can be accessed via a link in the site menu at the top of this page.

The natural place to start would be to take a look at Trevor Story’s rates in the minors, with an emphasis on the 2015 season. Last year, between AA and AAA, Story had 575 plate appearances, walking 51 times, amounting to 512 at-bats (256 at each level). He was also HBP 7 times and had 5 sacrifice flies, accounting for the other 12 plate appearances that make up the difference between 575 and 512.Story also struck out 141 times. In total, this amounted to a .279/.350/.514 line to go along with 20 HR. This was accompanied by a 8.9% walk rate and 24.5% K-rate, as well as a .346 BABIP. It should be noted that, while Story’s strikeout rate remained constant moving from AA to AAA (24.3% for the former versus 24.7% for the latter), his walk rate declined from 11.7% at AA to 5.8% at AAA. This makes sense considering that more advanced pitchers typically have better control, and are more capable of attacking the strike zone at the upper levels of the minors.

Now, looking at Story’s current rates for the 2016 season, which consists of only a 55 AB sample size, and I feel pretty comfortable saying that he has far exceeded his capabilities from a rates standpoint. To date, Story has put up a .360 BABIP, a 5.1% BB-rate, and a 39% k-rate. His batted-ball statistics currently stand at a 0.37 GB/FB ratio and a 42.1% HR/FB rate. The .360 BABIP is actually somewhat believable given his high 2015 rate in the minors (.346) and his current 60.6% hard contact rate in the majors (which in and of itself is unattainable, but we will give Story the benefit of the doubt in that regard). And, while FanGraphs does not track batted ball rates for players in the minors, we can compare Story’s current rates to those of last season’s league HR leader Chris Davis. Davis hit 47 HR last season, a number that was accompanied by a 0.73 GB/FB ratio and a 29.4% HR/FB rate. Davis’s BABIP was .319. While some may feel that this number should have been higher given the league average of about .302 and the fact that Davis made soft contact on only 9.7% of the batted balls, his BABIP actually compares well with his GB/FB ratio, as ground balls typically garner a higher BABIP than fly balls, and Davis hit far more of the latter than the former. Putting the numbers for Story next to those of last year’s HR king, and it is pretty clear that the Rockies will be seeing major regression from the SS over the course of the season.

With all of the numbers lined up, there is nothing left to do but attempt to calculate a batting line for Story through the remainder of the season. First, there is the question of how many games Story will play the rest of the season. With 13 out of 162 out of the way, that leaves 149 potential starts for Story. I will give him the benefit of the doubt here and assume that he remains the starter through the rest of the season, even when Reyes returns. Lets give Trevor 14 games off, putting him at 135 additional starts through September. Next, this needs to translate into a number of plate appearances. Story has averaged 4.54 PA/Game thus far, so for consistency’s sake, I will keep that number the same. This means in 135 games, Story should see 613 more plate appearances. Given his current track record of regression in the walks department as he has moved from AA to AAA to the Majors, I feel that his 5.1% rate is probably in line with where he will stay. He also has one sacrifice fly so far and 0 HBP, which I will stretch out over 135 games, giving him an additional 10 SF. Therefore, of his 613 PA, I expect about 31 walks and 10 SF, for a total of 572 at-bats.

Next I need to find out how many Ks Story will have the rest of the way so that I can project how many balls will be put in play. While projecting a strikeout rate off of such a small sample size is nearly impossible, I will roll ahead with my attempt anyways. At AAA, Story had a 24.7% K-rate in 256 AB. So far in 2016, he has a 39.0% rate in only 55 AB. If these numbers are averaged, then they amount to a 29.3% rate. This seems fair for Story given his career track record. At this rate over 572 AB, I project an additional 168 Ks in 2016. Subtract the strikeouts, and we are left with 404 batted balls. From here, I will peg Story’s GB/FB rate at 1.04, the average between Chris Davis (0.73) and the league average in 2015 (1.34). In finding a reasonable HR/FB rate, I had to get a little creative. According to Fangraphs, a 15.0% is considered great. In Coors Field, I wouldn’t doubt that Story could carry a rate this high, especially since the ballpark average last season was 12.8%. League average, on the other hand, was 11.4%. Story is definitely above league average, and probably above the Coors Field average, so I decided on a rate of 13.07% (the average of 15%, 12.8%, and 11.4%). Lastly, I will lower his BABIP to his 2015 average of .346. As a disclaimer, these rates that I have chosen to use are far from perfect, however, without Story’s minor league rates at hand, they are the most reasonable numbers that I can come up with.

On the home stretch now, lets calculate a stat line. With a 1.04 GB/FB rate, and taking line drives out of the equation, Story is allocated 206 GB and 198 FB. Add in the 13.07% HR/FB rate, and Story adds another 26 HR to his total! Subtract 26 HR from Story’s total of batted balls, and he is left with 378 balls put in play. At a rate of .346, this means that he will have 131 hits the rest of the way that are not HR, for a total of 157 hits. A 572 AB season yielding 157 hits gives Story a .274 AVG. Add to that the 41 walks and sacrifice flies that were removed earlier, and Story will reach base 198 times in 613 plate appearances, for an OBP of .323. Since I do not have a projection for the number of doubles and triples that Story will be projected to hit, I will need to find his slugging percentage based on a player comparison. The closest comp that I could come up with was Kris Bryan, who hit .275 with 26 HR in 650 PA last season, for a SLG% 0f .488.

With AVG/OBP/SLG and HR numbers now projected, we have a 2016 stat line for Trevor Story the rest of the way. See below for the projections:

Trevor Story 2016 Projections (April 19th and forward): .

135 GP, 613 PA, 572 AB, 31 BB, 26 HR, .274/.323/.488, .811 OPS

2016 Projections (Total): .

148 GP, 672 PA, 627AB, 34 BB, 34 HR, .278/.326/.520, .846 OPS


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