Every shortstop in the top 10 at the position on the Player Rater is on a roster in nearly every ESPN league ... with one exception.
Marcus Semien currently ranks ninth, with a .279 batting average, five homers and four steals. Can the Oakland infielder keep up this pace and be a top-10 option at the end of the season?
Tristan H. Cockcroft: Well, sure, he can keep up his pace, since his .279 batting average, 17 home runs, 81 RBIs and 115 runs scored pace line isn't a far cry from his 2015-17 per-162-games-played line of .248-22-65-14-78 (categories in the same order), but that doesn't mean that I'd pay or value him in that tier. Semien's problem is that he's not anything special in terms of batting average, his quality of contact is beneath league-average, and he's only a league-average walker. In short, he's an accumulator who has managed top-20 positional Player Rater finishes in 2015 and 2016 and top-30 in 2017 despite only 85 games played thanks in large part to his tendency to steal 10-15 bases annually (including in the minors).
Semien's .335 batting average on balls in play isn't merely likely to come down, it's going to come down -- I would be floored if it didn't considering his skill set. He has never managed better than .323 in a pro campaign and has a .301 career big-league mark, and when that settles back in the league-average range, he's going to be a .250-or-so hitter, and that's going to slow his runs-scored pace to something closer to his three-year average. I think that three-year average is nearly spot-on, and it's not that it's a bad line, but it's one that belongs in the "mixed league middle infielder" class, especially in ESPN leagues where a decent handful of players will pick up that eligibility in-season and flood the pool with comparable talent.
I count at least 12 current shortstop-eligibles I consider a lock to finish higher than Semien on the Rater (Francisco Lindor, Manny Machado, Trea Turner, Carlos Correa, Javier Baez, Didi Gregorius, Alex Bregman, Trevor Story, Jean Segura, Tim Anderson, Xander Bogaerts, Andrelton Simmons), and would anticipate Semien finishing somewhere in the 16th-18th range he did in his previous two fully-healthy seasons. They do different things, but I think he, Asdrubal Cabrera and Jose Peraza will finish in roughly the same range, and should be valued similarly.
AJ Mass: Semien is tricky case to analyze because he broke out in 2016 with an unexpected power surge (27 HRs, 14.7 percent HR/FB rate) and then he fractured a wrist in April last season, costing him nearly half of the season and making it hard to use any of his 2017 performance at the plate as a true comparison point.
Still, he's hit safely in 40 of 48 games this season and has 17 multi-hit games to his credit -- so the career-high .279 batting average doesn't seem to be over-inflated due to one hot streak and a small sample size. He could well continue at near that pace. I don't think he'll get anywhere near his 2016 power numbers as his HR/FB rate seems to be back to a "normal for him" 9.1 percent. However, 18-20 HRs seems doable for Semien, to go along with about a dozen steals.
Shortstop is a loaded position this season, so whether or not he finishes in the top 10 on the Player Rater will rely on the ability of his teammates to drive him in. In that regard, I think he'll fall a bit short.
Kyle Soppe: It's been a good start to the season for Semien and I am happy for anyone who has jumped on for the ride, but I am not expecting him to finish this season as a top-10 shortstop and would be surprised if he was even a starting MI from this point forward. Part of the argument against him is the talent that currently ranks below him on our Player Rater (Carlos Correa, Alex Bregman, and Xander Bogaerts) along with some potential options (Gleyber Torres and Chris Taylor to name two).
If Semien finishes the season at roughly the production level that he has given us throughout his career, I think it's possible that most, if not all, of those SS eligible players pass him and thus knock him out of the top 10. As for Semien himself, an .899 OPS with runners in scoring position seems a bit unsustainable given his .712 rate from the previous three seasons and I'm not buying his power as anything more than ordinary. Consider this, he already has not one, but two homerless streaks exceeding 75 at-bats. That's not to say that I am cutting ties with Semien, but I'd manage expectations moving forward.