While the enduring memory of the 2016 season is going to be the Cubs finally breaking free of 108 years of struggle to win a ring, the enduring effect is going to be something much different. The way Terry Francona used relievers Andrew Miller and Cody Allen (replicated in part by a few other teams as well) in order to push the Indians' depleted pitching staff to Game 7 seems for all the world to be the precipice of a new age of pitcher usage.
Given how success always breeds imitators, there may be no more pressing question for teams this offseason than this: How do you find the next Miller? That is, which struggling starting-pitcher candidates -- Miller, remember, had a 5.70 ERA in 66 career starts from 2007-11 -- may be the best bet to turn into successful relievers? Let's see what we can do to help them.
The first thing to understand is that the players who have done this successfully think a big part of it is between the ears.
"I think it's a different mindset," Miller said earlier this year.
"It's a mentality thing, to be honest," echoed Oakland's Liam Hendriks, who had a 5.95 ERA in 34 starts from 2011-14 before becoming a quietly effective reliever in 2015-16.

"I think that certain people, the bullpen just works better for them," said Hendriks. "For me, it was just that as a starter, I would always try and nitpick too much; while out of the 'pen, it's just a 'Here you go, try to hit this' kind of mentality."
As a starter, Hendriks allowed a woeful .305/.357/.509 line against and a 13.3 percent strikeout rate to go with that inflated ERA, but he had a very good .270/.305/.398 line against and a 26.5 percent whiff rate in 111 games as a reliever over the past two seasons, so he seems to know what he's talking about.
There's not much we can do about identifying the right personalities for the Miller role, but what we can do is identify the traits that seem to come along with helping struggling starters become quality relievers. The three that come to mind:
1. Velocity often increases
2. Least effective pitches can be dropped
3. Durability issues may be less impactful
Being able to throw harder in shorter stints is always the first item people think of, and we saw it with both Hendriks and Miller. Hendriks was in the 91-92 mph range as a starter, and he reaches 95-96 mph as a reliever. Miller was 92-93 mph in the rotation, and now also sits at 95-96 mph in relief. But as Miller was quick to remind, it's not only about that.
It's also about not having to throw pitches that don't work, since you won't see hitters more than once per game. Miller brought up a fair point about starters, asking, "How many starters have a good third or fourth pitch?" When he went to the bullpen, he ditched an ineffective sinker and changeup to go fastball/slider full-time. Hendriks did the same, saying, "I threw a few of my pitches out the back door, so it was just fastball/slider. I threw the occasional curveball, but my changeup was almost nonexistent."

We've seen that often in starters who go to the bullpen. Zach Britton stopped throwing his slider, change and four-seamer. Joe Blanton eliminated his cutter and sinker. Travis Wood threw six pitches as a starter, and now only throws three; Boston's Joe Kelly dropped his change and sinker to focus on four-seam/curve/slider. The list goes on.
So who's out there that fits our criteria -- who hasn't been able to make it work as a starter, either because of repertoire or durability issues, yet has the one plus pitch necessary to at least consider a move with? You could make an argument for dozens, probably, but here's three: 

Michael Pineda, Yankees
Set aside for a moment the reality that the Yanks' rotation is so thin that they probably can't shift Pineda, because that's more about the team than the pitcher. Pineda throws hard, averaging 94.8 mph on his fastball, and he's got a true wipeout pitch in his slider (.196 career average against), which had the seventh-best whiffs-per-swing rate of the 137 pitchers to throw 100 this year -- behind, among others, stars like Max Scherzer, Corey Kluber and Noah Syndergaard.
Gif: Michael Pineda strikes out Josh Donaldson
Yet Pineda has a 4.60 ERA over the past two years as a starter, in part because the fastball is relatively straight, and also because his other secondary pitches aren't effective. Dropping those and turning Pineda into a fastball/slider pitcher -- potentially adding another kick of velocity onto an already hard heater -- might add the value we've not seen recently in the rotation, and it would change Pineda's profile heading into his free-agent showcase season.
Andrew Cashner, Free agent
Cashner's profile isn't that different from Pineda. He also throws hard (94.5 mph on his four-seam fastball), but he's made six trips to the disabled list in his career, half of which were for right arm issues, with two coming in 2016 (hamstring, neck). Despite the velocity, Cashner's performance hasn't matched the reputation that led to San Diego trading Anthony Rizzo for him prior to '12. Of 312 pitchers with 100 innings over the past two seasons, his 4.72 ERA is 259th. Cashner has been neither dominant nor durable.
Like Pineda, the slider has been Cashner's best strikeout pitch, and there's evidence that it got better late last year, adding velocity and bite in part thanks to a new grip. Imagine a version of Cashner that (potentially) threw harder in shorter stints?

Jarred Cosart, Padres
The thing about Cosart, who was sent to San Diego in the deal that shipped Cashner to Miami, is that he already pitches like a reliever. Cosart throws his cutter and his curve more than 90 percent of the time, sometimes dropping in a rare changeup. Over the past three seasons for three teams, the performance hasn't really been impressive, striking out a mere 200 in 307 innings with a 4.31 ERA.
Gif: Cosart strikes out Granderson
Cosart is still only 26, though he did undergo elbow surgery following the season. But he can get the cutter up to the 93-94 mph range, and it does have just a .207 average against for his career. And as you'd expect from a pitcher with so few pitches, Cosart gets hammered the third time through the order. For his career, his wOBA allowed is .301 and .290 the first two times through, jumping to .359. (Major League average wOBA in 2016 was .318). Cosart is a perfect candidate for short relief work -- especially if that cutter starts coming out at 95.