The symptoms

Let's start by looking at Paul Goldschmidt's production so far, and see how it compares to previous seasons.

Batting average down . Goldschmidt hasn't hit less than .300 for a full season since 2012. He is currently hitting .234.



. Goldschmidt hasn't hit less than .300 for a full season since 2012. He is currently hitting .234. Strikeouts up . Though not as much as I perhaps thought. Paul has always had his share of K's - he was tied for 7th in the league last season - but the raw number of K's is exacerbated by him leading the NL in PAs thus far. Still, the strikeout rate has definitely increased from 21.7% in 2015, to 24.0% thus far,

. Though not as much as I perhaps thought. Paul has always had his share of K's - he was tied for 7th in the league last season - but the raw number of K's is exacerbated by him leading the NL in PAs thus far. Still, the strikeout rate has definitely increased from 21.7% in 2015, to 24.0% thus far, Unintentional walks up . Goldschmidt is on pace for 167 walks this season. Barry Bonds and Babe Ruth are the only baseball players ever with as many as that. However, almost no-one is putting up four fingers for Goldy any more: last year, intentional walks were close to a quarter of his tally (29 of 118). This year, it's only three of 35.



. Goldschmidt is on pace for 167 walks this season. Barry Bonds and Babe Ruth are the only baseball players with as many as that. However, almost no-one is putting up four fingers for Goldy any more: last year, intentional walks were close to a quarter of his tally (29 of 118). This year, it's only three of 35. Doubles evaporated. His home-run numbers are almost unchanged, projected for about thirty. But where have all the two-baggers gone? Here are Goldschmidt's doubles for each season from 2012 through 2015: 43, 36, 39, 38. This season? Three: That's the same number as Rickie Weeks Jr. Before last night, Goldschmidt was not even on pace for double-digits. [H/T @DBackMac for pointing this out]



The causes

Let's dig a little bit further into the underlying numbers and see if we can find out what is driving the change in Goldschmidt's output this season. Here are the metrics for Paul which have shown the most dramatic difference from last year - some of these are inter-related, but we'll get to that.

First-pitch hacking: 17.9% (24.3%).

Swing %: 33.8% (39.4%)

Strikes looking: 38.6% (32.2%)

BABIP: .282 (2015: .382)

Infield Fly %: 12.6% (5.4%)

Line-drive %: 23% (33%)

Softly-hit %: 23.4% (10.2%).



Pull %: 41.6% (29.6%)

- Paul Goldschmidt "I’ve been feeling good. I know the results haven’t been there, but that’s just part of it. I’m just trying to go out there and have good at-bats, hit the ball hard and hopefully find a way to get on base."

Chip Hale said, "I think he just has to be a little more aggressive in the zone. It seems like every time you look up, he’s hitting with two strikes. He’ll even tell you he’d like to be a little more aggressive earlier in the count." There is some truth to this, but only some. Last year, Goldie reached two strikes in almost exactly half his PAs. This year, that number is up to 60%. It begins with the first pitch, where he is swinging about 30% less that he did. However, that isn't translating into 0-1 counts. In 2015, there was almost an even split: 317 counts of 1-0, 316 of 0-1, and 62 PAs ended on the first pitch. This year, the same numbers are 72, 66 and 12, so he's initially getting ahead a bit more .

What has perhaps changed more, is what Goldy is doing in those two strike counts. He was one of the very best in baseball with two strikes last season, hitting .252 - league average was only .174. But this season, Goldschmidt's line with two strikes is down to .155/.333/.324; However, the main issue to me seems to be the kind of balls in play he is producing: the "good ones" are sharply down, and the bad ones are markedly higher. Infield flies, for example, are all but guaranteed to turn into outs, while line drives have a much better chance at becoming hits. Combine those two, both going in the wrong direction, and you're a long way down the road of explaining why Paul's BABIP has dropped by 100 points.

We see this in a sharp uptick of "soft" balls in play off the bat of Goldy, almost entirely taken from the "hard" category. In 2015, Goldschmidt was fourth among all qualifying batters with a hard-hit rate of 41.4%. That has plummeted to well below league average, Paul's figure for 2016 of 31.2% now ranking him 113th. This may well explain where all the doubles have gone. Soft balls in play, even if they don't hang up long enough to become outs, have a much better chance of being cut off by an outfielder and the hitter having to stop at first, rather than finding a gap and going to the wall, leading to extra bases for the batter.

Also perhaps of interest, Goldschmidt has become much more of a pull hitter than he was in 2015, when he was slightly more likely to go the other way, than pull the ball to left-field. So, we have Paul v.2016 apparently getting under the ball, leading to a high percentage of easy pop-ups, and being too quick to pitches, resulting in a "hook," rather than the previous, even spray distribution of hits to all fields. I'll leave it to those who have more knowledge of hitting mechanics than I (likely just about everyone!). to discuss the specifics of what might be causing this

The cure

Last night was hopeful, and maybe Coors Field will be the cure for what has ailed him, but I'm not going to proclaim a trend after one game. It's possible this may simply be bad timing; any form of streak is always highlighted at the beginning of the season. Goldschmidt actually had an even worse slump over a longer period, covering more than a quarter of the season last year - but nobody really noticed, because it came late, and he had been hitting .349 to that point. Over 41 games from the beginning of August through September 15, Goldschmidt's line was .235/.350/.430, with a 30% strikeout rate and 14% walk-rate.

On the other hand, tie ot together with this one, and you could say since August 1, Goldy has 91 games and batted only .259 (albeit with walks and power). An undisclosed injury of some kind? You never know, but Hale flat out denied it: "He says he's 100 percent. In fact, that's why I haven't given him any days off. The weather was great in Miami and Atlanta. He says he feels strong, he feels good, he takes great care of himself." This may simply be our medical paranoia. After the unexpected and bizarre loss of A.J. Pollock, who broke his elbow getting up from the ground, we can perhaps be forgiven for twitching nervously whenever Goldy gives the slightest sign of being nicked.

Mechanical issues? Hale rejected that too: “His mechanics are very simple. It’s not a lot of movement in his swing. His legs are spread. There’s not a whole lot you can mechanically change, unless you want to make it more complicated, which we don’t. I don’t think that’s an issue at this point.” Beyond that, I'm entirely open to suggestions, and throw the floor open to these. As goes Paul Goldschmidt, so go the Diamondbacks, and a Goldy that's firing on all cylinders would be a significant help to any chance of Arizona competing in the NL West this year.