Marcus Stroman Heads to The Big Apple

In our first big trade of the non-waiver trade deadline season, Marcus Stroman joins the New York Mets, at which point Mets fans know all too well that he’ll turn into a pumpkin and never be effective again until he’s traded away. In all seriousness the knee-jerk reaction is that this move is fantastic for his fantasy value, given a more pitcher friendly venue and a switch to the National League. Let’s dive into the park factors to get more clarity on the change in home parks.

Well gosh darn, it’s not often you see a near sweep in a ballpark factor comparison. You’ll see in the two factors that begin the comparison, the 3yr and 1yr, Citi Field (Mets) has been significantly more pitcher friendly than the Rogers Centre (Blue Jays). Those represent the three and one year overall run park factors and ultimately are most important.

In literally every hit type, Citi comes out ahead. It has suppressed singles to a greater degree, and the gap in factors for doubles and triples is even larger. This is important, because as one of the league’s most extreme groundballers, Stroman has been prone to inflated BABIP marks. His career .306 mark is above the league average that generally sits in the mid-.290 range.

For both hitters and pitchers, home run park factors are also quite impactful. Citi once again is far more pitcher friendly, as Rogers actually inflates homers. As an extreme groundballer, Stroman doesn’t allow a high rate of fly balls, so he won’t be as affected by a change in factor here as much as a more fly ball prone pitcher. But still, this is obviously a positive for his performance at Citi.

The strikeout and walk factors are very similar, both parks being about neutral in both. Amazingly, despite a vast pitch repertoire, Stroman has only posted a strikeout rate above 20% once, and that was during his 2014 debut. The spike I keep expecting to occur at any time continues to get delayed to the point that it’s silly to expect it to ever happen. However, the move to the NL should provide the best opportunity for a boost there has ever been. If he can’t get that strikeout rate above 20% while pitching in the NL, there’s no hope!

The most important batted ball type factors to pay attention to are LD and IFFB. The line drive rate factors are near identical, while Citi’s IFFB factor is dramatically higher. That’s usually a very good thing for a pitcher, but Stroman has never induced a high rate of pop-ups, for two reasons. One, he doesn’t allow enough fly balls, so even if his IFFB% (remember that metric is a percentage of fly balls) was higher than the league average, his IFFBs induced would still be rather low. And two, his IFFB% has always been well below average anyway, resulting in a super low number of pop-ups. This year is the first he’s gotten it into double digits, as he has already induced more pop-ups than the last two seasons combined.

Overall, it’s pretty obvious that between the park switch and the league switch, this is an excellent move that boost Stroman’s fantasy value. This doesn’t actually mean that he’ll earn more value the rest of the way than he has though, as you must keep in mind that his ERA sits more than a run below his SIERA. But at least there’s less chance his luck regresses and his SIERA declines to meet his ERA rather than the other way around.