Of all the free-agent outfielders out there this offseason, only one could really be considered an above-average all-around everyday player. Sure, J.D. Martinez can mash with absolutely anyone, but his defense isn't a strength. Yes, Jarrod Dyson is a fantastic defender, but he doesn't bring a bat to match. If teams are looking for an above-average bat paired with a top quality center-field glove, there's only one name available: Lorenzo Cain.
Despite the fact that Cain has somehow never won a Gold Glove Award, he's long been one of the best outfielders in the game. In 2017, he finished fifth in Outs Above Average (the Statcast™ range-based outfield metric) with +15; in '16, he was tied for ninth with +12.
While it's true that Cain will be 32 in April and that speed tends to peak early, he's starting from such a high place -- in the top 4 percent of speed, according to Statcast™'s Sprint Speed, similar to Trea Turner -- that even some age-based decline should still allow him to be a plus defender. But where? And how much would he help on defense? We can investigate.
In order to do so, we've narrowed this down to five potential new homes where he'd really help. There's other spots where he'd be a fielding upgrade, of course, but for example, the Pirates aren't going to bring him in to replace Andrew McCutchen; the Cardinals just made their big outfield splash for Marcell Ozuna; the Orioles have indicated they aren't considering moving Adam Jones to a corner; and the Mets seem content to ride with Juan Lagares, who has a glove as good as Cain's if he can stay healthy.
So, we'll stick to our top five -- and we'll show you some side-by-side videos that illustrate opportunities that Cain made compared to similar plays that weren't made by the guys who played center in 2017 for these teams.
Giants

Span: 64 feet away, 3.9 seconds of opportunity time. Cain: 62 feet away, 3.9 seconds.
The Giants, in a lot of ways, are the perfect fit, especially after missing out on Giancarlo Stanton. Team management has been very open about the fact that improving outfield defense is a priority, and incumbent center fielder Denard Span (who had -12 Outs Above Average, tied for second fewest) was preparing for a move to a corner spot before he was sent to Tampa Bay in the Evan Longoria deal. While San Francisco may not want to block prospect Steven Duggar, either Duggar or Cain could play a corner when Duggar is ready in 2019.
If you look at the difference between Cain's +15 Outs Above Average and Span's -12, we're talking 27 outs in center field alone; there's a reason pitchers Jeff Samardzija and Mark Melancon each appeared on our list of pitchers who deserved better. San Francisco's outfield defense hurt its pitchers, and there's no better way to upgrade than Cain -- even with the Giants' issues surrounding the luxury tax.
Blue Jays

Cain: 80 feet away, 4.3 seconds of opportunity time. Pillar: 86 feet away, 4.5 seconds.
Toronto's inclusion on this list might be shocking, given that Kevin Pillar has a fantastic reputation and probably makes more great-looking catches than any outfielder in the game, yet there are credible rumors that the Blue Jays are in on Cain, and for two very good reasons.
First, for all of Pillar's highlights, the metrics indicate he's losing a step. In 2016, he was sixth in OAA, at +15; in '17, he dropped all the way to -2, a huge decline. You don't have to buy into advanced metrics to see it, either; Pillar has played a similar number of innings in the last three seasons, and his raw putout numbers have dropped from 440 to 337 to 316. He's just not getting to as many balls as he once did.
But secondly, the Blue Jays need defensive help everywhere in the outfield after they ranked last in team Outs Above Average at -22. They won't repeat a year where Ezequiel Carrera, Steve Pearce and Jose Bautista received the bulk of time in the corners, so even if Pillar had to shift, it would be a huge win. After all, there's a reason Marco Estrada saw his ERA jump from 3.48 to 4.98 despite relatively similar performance on his part.
Rockies

Blackmon: 65 feet away, 4.2 seconds of opportunity time. Cain: 63 feet away, 4.0 seconds.
The Rockies are in a similar position as Toronto, in that they have a center fielder with a good reputation in Charlie Blackmon but could stand to improve in two spots by putting Cain in center and shifting their incumbent star to a corner. Blackmon does a good job (his -1 OAA made him basically average), but the Rockies don't need a good fielder there. They need a great one, because contrary to popular opinion, the difficulty in Denver isn't home runs; it's extra-base hits falling in because the size of the outfield is simply massive.
With Carlos Gonzalez a free agent and unlikely to return and the health status of the talented young David Dahl still an open question, the Rockies could easily put Cain in center and shift Blackmon to a corner. Not only would that help the defense, it would help the lineup, where the Rockies badly need another bat. Cain hit .300/.363/.440 with 15 homers and 26 steals last year, and while Blackmon was a stud, Colorado finished in the bottom five in park-adjusted offense in both left field and right field.
Dodgers

Pederson: 60 feet away, 4.3 seconds of opportunity time. Cain: 59 feet away, 4.2 seconds.
The defending National League champs have few holes to fill, but they also have an outfield situation that's somewhat unsettled. The outfield, as a group, finished tied for 25th with -9 OAA, largely because of Joc Pederson and his -8. The Dodgers know this; after parts of three seasons as the primary center fielder, Pederson played mostly left in the playoffs as converted infielder Chris Taylor handled center, and they've asked Pederson to improve his conditioning.
There's a lot of moving parts here. Cody Bellinger can play the outfield, but he won't, because with Adrian Gonzalez gone, Bellinger will be at first. Alex Verdugo can play center, unless he's back in Triple-A. Taylor can play center, unless he's back in the infield, or can't repeat his breakout hitting season. Pederson has played center, until he didn't. Maybe Alvin Toles will be playing left -- unless he's in center, or neither, if his surgically-repaired knee is troublesome.
In a situation where there's more questions than answers -- and we haven't even discussed Yasiel Puig -- Cain would be a perfect fit in center, adding defense, a strong bat, and reliability.
Rangers

Gomez: 69 feet away, 4.1 seconds of opportunity time. Cain: 70 feet away, 4.1 seconds.
The Rangers have been busy improving their pitching staff this offseason, signing Mike Minor, Doug Fister and Chris Martin, with more likely to come. What better way to help their pitchers than by improving the gloves behind them? Rangers outfielders tied for 18th with -5 Outs Above Average last year, and 2017's primary center fielder, Carlos Gomez, is a free agent.
Texas does have Delino DeShields, one of the fastest players in baseball, but all that speed hasn't yet translated into elite defense. (DeShields had a -2 OAA in 2016 and +4 in 2017, making him roughly average, though he's merely a .254/.333/.360 career hitter.) He actually spent more time in left than in center in 2017, and he may need to do so again, because rookie Willie Calhoun's best position is "hitter."

DeShields: 53 feet away, 3.5 seconds of opportunity time. Cain: 47 feet away, 3.5 seconds.
We know that Texas has been interested in Cain in the past. We know that no pitching staff in 2017 racked up a lower strikeout percentage than the 17.8 percent from the Rangers, leading to a ton of balls in play, and we know that there's no better time than now, especially with the Astros having just won it all, and the Angels loading up with Shohei Ohtani, Zack Cozart, and Ian Kinsler. The Rangers need to improve their run prevention, and there's more than one way to do it.