What is going on here and why is this happening? I have seen 20-30 of Pedro's Abs which is a very small sample size and I don't have the fundamental knowledge to make any conclusions on his swing. What I can do, though, is look at Fangraphs. Last season, Pedro's triple slash in the majors was 256/326/461. The power ISO (SLG - BA) was 205, the wRC+ was 111 (above average). After a lousy first two weeks, he went on to put up OPS of 855, 735, 936 over the last three months (averaging out to 842). Contrary to popular belief, his numbers were not solely the result of a good September. He hit pretty well in July and August too. This was a very good rookie season. That's why his disastrous sophomore campaign has been so surprising. This year he has put up a 203/273/294 triple slash. Wow!
What the heck happened? From simple inspection, the BA is down 50 points but the ISO is down 100 points. Is he striking out way more? No. The K rate hasn't gone up much, but the BABIP and power have completely disappeared. It is surprising to note that his Z-swing %age (fraction of strikes that he swings at) is normal at 65.5%. He also doesn't swing at an abnormally high number of would-be balls. These numbers are qualitatively similar to last season.
How about his ability to make contact with the pitches he does swing at? With balls in the strike zone, he is 6.8% below league average (only slightly worse than last year).His ability to make contact on balls out of the zone is actually much higher than last season though still 13% below league average. Overall, his contact % is a little bit higher than last season.
What type of balls does he hit when he does put them in play? Here is where some big differences relative to last year emerge. His GB/FB ratio is way up (1.15 to 1.97). His LD% is up significantly (14.8% to 19%) and his HR/FB ratio is way down (17.6% to 9.1%). Ground balls and liners should cause the BABIP to go up, so I conclude that he is making weaker contact and so the BABIP and ISO are way down, despite the increased LD%. This also explains the reduced HR/FB.
So why is he making weaker contact? Looking back on the statistics, his contact rate on balls out of the zone has improved from 47.5% to 55.6% and my hunch is that he doesn't hit those balls very hard. His efforts to make more contact with pitches out of the zone are hurting him because whereas those used to be swinging strikes, now they are outs. One thing that the plate discipline statistics probably do not capture is the fact that Alvarez is taking a lot of very crushable pitches, if there were a meatball swing %, I'm sure he would be way below average. Another thing that these statistics don't capture is the fact that a lot of those GBs are due to him trying to pull low and outside pitches. I am not knowledgable enough to comment on his swing mechanics.
So how does he snap out of this? I see two things he must do. First, he must go with the pitch - he has the ability to hit to left field with power, I've seen him do it before and he must dedicate himself to doing this. Second, he needs to be ready to crush a mistake in any count. If the first pitch is a belt high fastball then he has to be mentally ready to kill it. Given his performance over a three month sample size last year, I still believe that he possesses the talent to be an 850 OPS hitter in the majors; I think that his problems right now are all in his mind and they are correctable. What do you see?