So, I've done a lot of research on Porcello ever since Gammons came out with the comments that Brian Bannister has made alterations to his pitch mix. You can certainly see how his pitch mix changed from April - July vs Aug/Sept.
http://www.brooksbaseball.net/outcome.php?player=519144&b_hand=-1&time=month&minmax=ci&var=pcount&s_type=2&gFilt=&pFilt=FA|SI|FC|CU|SL|CS|KN|CH|FS|SB&startDate=01/01/2015&endDate=01/01/2016
Anyway, post DL stint, when he changed his pitch mix, he posted a 3.14/2.96/2.96 ERA/FIP/xFIP. Unfortunately, that only spanned about 57.1 IP, so I wanted to do a little more digging.
I grabbed Porcello's pitch mix from Brooks from his career game log and lined it up with his game log from Fangraphs, which allowed me to filter on his results by pitch mix. The results? Pretty encouraging.
Filtered on the following (all consistent with post DL usage):
4 SM FB: 12-23%
2 SM FB: 40-60%
Curveball: 5-14%
Cutter, Change, and Slider all didn't change by any kind of a significant margin.
EDIT: To clarify on his Change, once the 4sm, 2sm, and Curveball were all filtered, the remaining results of his change (which did see an increase in usage, but ranged from 7%-25% during those post DL starts) were all consistent with the usage in his post-DL starts (i.e., they were all within the 7-25% usage range), thus no filter needed, if that makes sense
Career Results:
IP 159.00
K/9 6.96
BB/9 2.04
ERA 3.85
xFIP 3.55
This, however, goes back to when he was called up too early, and natural progression with age, I thought, should make these results even better.
2012-2015:
IP 130.00
K/9 6.99
BB/9 2.22
ERA 3.53
xFIP 3.55
xFIP doesn't change much at all, but ERA begins to match xFIP.
2013-2015:
IP 105.00
K/9 7.29
BB/9 2.31
ERA 3.34
xFIP 3.54
Again, xFIP stays around the 3.55 range, ERA beginning to improve upon xFIP, likely due to an increase in downward action on his sinker resulting in a lower than average HR/FB.
The more encouraging results are below:
2014 - 2015
IP 71.33
K/9 8.20
BB/9 2.02
ERA 3.28
xFIP 3.26
K/9 has increased, xFIP drops down into a well above average rate, and ERA matches. Again, we're limiting the IP here, but if you're going with K rate and BB rate as the main drivers (which they are for xFIP), both stabilize over 170 Batters Faced or less, and that criteria has well been met here.
So what do I take away from my research? Well, to project Porcello to morph into a 3.25 ERA pitcher is a little aggressive. That said, he's got a substantial amount of data that indicates that, with Bannister's help in game planning around a specific pitch mix, he can certainly be the 2016 version of 2013 John Lackey and post an ERA/xFIP in the 3.4-3.55 range. And that, I believe, would be plenty good enough to stick behind Price as your number 2.
http://www.brooksbaseball.net/outcome.php?player=519144&b_hand=-1&time=month&minmax=ci&var=pcount&s_type=2&gFilt=&pFilt=FA|SI|FC|CU|SL|CS|KN|CH|FS|SB&startDate=01/01/2015&endDate=01/01/2016
Anyway, post DL stint, when he changed his pitch mix, he posted a 3.14/2.96/2.96 ERA/FIP/xFIP. Unfortunately, that only spanned about 57.1 IP, so I wanted to do a little more digging.
I grabbed Porcello's pitch mix from Brooks from his career game log and lined it up with his game log from Fangraphs, which allowed me to filter on his results by pitch mix. The results? Pretty encouraging.
Filtered on the following (all consistent with post DL usage):
4 SM FB: 12-23%
2 SM FB: 40-60%
Curveball: 5-14%
Cutter, Change, and Slider all didn't change by any kind of a significant margin.
EDIT: To clarify on his Change, once the 4sm, 2sm, and Curveball were all filtered, the remaining results of his change (which did see an increase in usage, but ranged from 7%-25% during those post DL starts) were all consistent with the usage in his post-DL starts (i.e., they were all within the 7-25% usage range), thus no filter needed, if that makes sense
Career Results:
IP 159.00
K/9 6.96
BB/9 2.04
ERA 3.85
xFIP 3.55
This, however, goes back to when he was called up too early, and natural progression with age, I thought, should make these results even better.
2012-2015:
IP 130.00
K/9 6.99
BB/9 2.22
ERA 3.53
xFIP 3.55
xFIP doesn't change much at all, but ERA begins to match xFIP.
2013-2015:
IP 105.00
K/9 7.29
BB/9 2.31
ERA 3.34
xFIP 3.54
Again, xFIP stays around the 3.55 range, ERA beginning to improve upon xFIP, likely due to an increase in downward action on his sinker resulting in a lower than average HR/FB.
The more encouraging results are below:
2014 - 2015
IP 71.33
K/9 8.20
BB/9 2.02
ERA 3.28
xFIP 3.26
K/9 has increased, xFIP drops down into a well above average rate, and ERA matches. Again, we're limiting the IP here, but if you're going with K rate and BB rate as the main drivers (which they are for xFIP), both stabilize over 170 Batters Faced or less, and that criteria has well been met here.
So what do I take away from my research? Well, to project Porcello to morph into a 3.25 ERA pitcher is a little aggressive. That said, he's got a substantial amount of data that indicates that, with Bannister's help in game planning around a specific pitch mix, he can certainly be the 2016 version of 2013 John Lackey and post an ERA/xFIP in the 3.4-3.55 range. And that, I believe, would be plenty good enough to stick behind Price as your number 2.