The remarkable rise of Daniel Descalso

In some ways, Daniel Descalso’s 2018 has been just like his 2017. He has started at every position in the order from first through seventh, appeared at all four infield spots, plus left-field and designated hitter, and been far and away the clutchiest of clutch hitters, extending his reputation in such things. But I doubt anyone predicted Descalso and his career OPS+ of 81 coming into his ninth season, would lead the D-backs’ active roster (min 100 PA) there. Yet Daniel is at 126 as we enter the Giants’ series, on pace for career highs in just about every offensive category. Sean’s away this week, but before he left we exchanged emails about how this rise might be worth looking at in more detail.

Descalso’s walk-rate and strikeout rate haven’t changed very much from last season, but he has still seen a very significant power surge. His ISO (slugging % minus batting average) has spiked to .257, up from figures of .163 and .160 the previous two years. The other number which jumps out in his overall stats is the fly-ball rate. He had always been slightly skewed that way: from 2010-16, his ground-ball/fly-ball ratio was 0.87, a little below the MLB average of 0.92. But in 2017, especially in the second half, he started hitting more fly-balls, and the ratio dropped to 0.65. That trend has continued, and so far in 2018, it’s down to 0.43. Only three NL hitters with as many PA as Descalso, have a lower ratio.

It’s particularly notable if you look at Descalso’s average launch angle. A quick reminder of why this matters, courtesy of Josh Donaldson [the whole article is worth a read]: “If you look at a baseball field and look on the infield, there’s a lot of players there. There’s not as much grass. But you look in the outfield, there’s fewer players and more grass. So if you hit it in the air, even if it’s not that hard, you have a chance.” The article concludes, “Look around the majors now, at players who make significant year-over-year leaps in performance, and there is a good chance at least part of the improvement is a result of hitting the ball in the air with more frequency and authority.” Here are Descalso’s launch angles:

• 2015: 11.2 degrees
• 2016: 10.0 degrees
• 2017: 12.7 degrees
• 2018: 21.5 degrees

It’s a striking difference. Descalso has increased his average launch angle by 69% over the figure from last year - already a career high - and is having far and away the best season of his life. That launch angle represents the fifth-highest in the majors among players with 100+ results to analyze. [If you want more proof of its relevance, drop the qualification to 50+ results. #1 in launch angle is the other 2018 breakout on offense for Arizona, John Ryan Murphy, who has jacked up his launch angle even further this season, to 26.9 degrees. This goes a long way to explaining his insane HR/FB rate.] Added to that, Descalso’s exit velocity is also at a career high of 89.0 mph, with a hard-hit percentage of 38.7%.

Two other things stand out in this year’s version of Daniel Descalso. He’s pulling the ball a good deal more, over 48% of the time. compared to 38-39% the previous three years. This is shown on the spray chart above, with his 2017 batted balls on the left, and 2018 on the right. This helps illustrate the increased launch angle too: you don’t see in this year’s chart quite the same “wall of groundballs” between first and second, which was present last season. He’s now hitting the ball over those infielders, though it’s worth noting, opposing defenses have adjusted, and are now shifting the infield much more on Descalso this season - 22.7% of the time, compared to just 6.6% last year.

He is also doing much more damage against fastballs. He is batting .341 against them, with an average exit velocity of 91.3 mph; the same figures for 2017 were .226 and 87.7 mph. Some teams appear to have noticed, with the percentage he’s seeing down to 58.9% from 63.6%, and it would not surprise me if the number continues to drop, given Daniel’s greater success against them. That’s really the key as to whether this surge is sustainable or not. Opposing teams are going to adjust the way they pitch to and defend against Descalso. He needs to adjust his approach at the plate appropriately, in that never-ending game within the game.