Yesterday, I continued my annual tradition of polling you on groups of players falling into two performance vs expected buckets, by comparing hitters’ wOBA against their xwOBA. Today, let’s finish things off by comparing starting pitchers’ ERA to SIERA, pitting the SIERA overperformers against the underperformers during the pre-all-star break period. This is the poll I began with back in 2013.
The All-Star break is here! That means it’s time to get polling. As has become an annual tradition, I’m going to start by comparing batter wOBA to xwOBA and pitting the xwOBA overperformers against the underperformers during the pre-all-star break period.
We know that xwOBA isn’t perfect (for example, it fails to account for horizontal angle, which certainly impacts results). Neither are SIERA, xERA, and the rest of the ERA estimators. In fact, no estimated/expected/forecasted equation is going to be perfect, because there will always be players that do something we have a difficult time quantifying. Furthermore, there will always be players each year that fall into either end of the extremes for no other reason than complete randomness (luck). So let’s keep that in mind when reviewing these two groups.
I last reviewed starting pitcher Stuff+ gainers and decliners about a month ago, so it’s time to take another gander at each group.
In one or several of my previous posts, I realized that a couple of starting pitchers that hit the Injured List had also recently suffered a decline in Location+. I haven’t seen a study that investigated whether a recent decline in the metric actually results in a higher chance of the pitcher landing on the IL and I’m not sure how such a study would be designed to begin with. So I don’t want to inspire panic among the owners of the 16 names on this list, but I figure it’s worth sharing as something to monitor, as it does feel like a sharp drop should be cause for concern.
Yesterday, I discussed seven recent hitter callups that have all been given starting job. Obviously, these names are going to be the priorities, particularly in deeper leagues where a recall fills a positional need. Today, let’s flip over to five more players who have recently been called up, but are currently serving in a bench role.
Trying to follow all the transactions on a daily basis can be head-spinning. Usually, it’s just a middle reliever, or a hitter expected to fill a bench role, that gets recalled from the minors. But that’s not always the case. So it pays to keep up with promotions on the chance that you just found yourself a replacement for that glaring hole you have at second base, for example. Let’s review seven of these recent hitter call-ups that look to have regular jobs.
In shallower formats, it’s true that non-closing relievers typically hold minimal fantasy value, assuming your league isn’t counting Holds. But in deeper leagues, especially mono formats, I would prefer to start a middle reliever over a slew of starting pitchers in order to preserve my ratios. Every day relievers are being recalled from the minors so it’s very difficult to keep up with the entire landscape. Since they usually fly under the radar, you should be able to catch newly dominant ones early when no one else is even looking.
It’s been about a month and a half since I last checked on the starting pitcher SIERA underperformers and overperformers. So let’s revisit these names to find out if any make good trade targets or opportunities to sell high on.
Who says only pitchers change throughout the season? Of course, batters do too, and with newfangled metrics like BatSpd, it’s easier to identify the driver(s) of such changes. So let’s identify and discuss the hitters whose BatSpd has changed most over the last 30 days compared to earlier in the season.
Though I’m not sure there’s a particular comparison study that makes such a definitive conclusion, it certainly feels like pitchers’ underlying skills are far more volatile during the season than batters. While that usually shows up in strikeout and walk rates, we also might see it in new stats like Stuff+. So it’s worth tracking recent trends to identify pitchers whose stuff has either improved or deteriorated as that could explain recent performance and potentially predict future performance better than if using stale Stuff+ marks.
