Sox acquire RHP Anthony Varvaro from Braves for RHP Aaron Kurcz and cash

[mauf]

Badenhop had a 4.56 xFIP against LHBs last year; his career xFIP vs. LHB is 4.81. He's a situational righty who's going to get overpaid based on his unsustainable 2.3% HR/FB last season.
 
Varvaro is likely to be better than Badenhop in 2015, at a lower cost, and with the upside of three more cost-controlled years if it turns out his 2014 numbers were a big step forward rather than a SSS anomaly.

 

[DaubachmanTurnerOD]

 
Mujica's FIP and xFIP by month.
April: 4.58, 4.92
May: 6.23, 3.96
June: 2.80, 2.04
July: 3.42, 3.84
August: 2.34, 4.19
September: 2.82, 3.84
 
Those xFIPs in August and September suggest he was decent, but nothing special and the difference between those numbers and his FIPs in those months suggests he may have been lucky with his HR/FB rate. The only month I'd say he was very good in is June. Of course, relievers have a lot of fluctuations in their performances if you break them down into small samples like we are doing here, so I'm not sure how much you can read into any of this. His overall line for the year was pretty poor, though he obviously had some bad luck in May so he's probably a good bet to be a serviceable middle reliever next year, and may eventually prove adequate as late inning depth.

Could there be an argument that in Mujica's case, we shouldn't put too much weight on the xFIP (vs. the FIP) since as a sinker-baller his HR rate shouldn't regress all the way to league average?

 

[williams_482]

Could there be an argument that in Mujica's case, we shouldn't put too much weight on the xFIP (vs. the FIP) since as a sinker-baller his HR rate shouldn't regress all the way to league average?

Actually the opposite is true. Sinkerballers give up less home runs, but typically have a higher home run to fly ball ratio (which xFIP normalizes to league average). 
 
SIERA is a really fancy* DIPS metric which takes that and other factors into account. Interestingly Mujica's SIERA (3.29) is consistently lower than his FIP (3.76) or xFIP (3.65) throughout his career, so take that as you will. 
 
*Note that it is not necessarily more accurate than the simpler metrics. Basic FIP does a remarkably good job at predicting future ERA relative to more sophisticated alternatives. 

 

[DaubachmanTurnerOD]

Actually the opposite is true. Sinkerballers give up less home runs, but typically have a higher home run to fly ball ratio (which xFIP normalizes to league average). 
 
SIERA is a really fancy* DIPS metric which takes that and other factors into account. Interestingly Mujica's SIERA (3.29) is consistently lower than his FIP (3.76) or xFIP (3.65) throughout his career, so take that as you will. 
 
*Note that it is not necessarily more accurate than the simpler metrics. Basic FIP does a remarkably good job at predicting future ERA relative to more sophisticated alternatives. 

Ahh...of course, Hr/fly ball makes more sense than simply HR rate. Thank you for the explanation.

As a further aside from the thread topic, didn't the guy(s) who developed SIERA do it for BP and then BP had a big article explaining that they were going to drop the statistic precisely because it was much more complicated and not much more accurate? And then Fangraphs promptly picked it up? I remember some scuttlebutt, and think the little BP/FG spats are sort of interesting.