The Indians finished spring training with a 20-9 record, giving them the most wins of any MLB team. That doesn't mean they should be expected to win more games than anyone else during the regular season (that simply isn't how this works), but there is some correlation between spring-training records and regular-season success, so it's better to have had the Tribe win 20 than lose 20.
Here are the teams from the last ten years that finished with the most spring-training wins, along with how they did in the regular season:
The median number of wins for those teams is 88.5, while 8 of the 10 won at least 86 games. ANother way of looking at things is to take each regular season's best record, and see how that team did in the spring. Over the last ten years, the 13 teams that finished with MLB's best record each year (13 not 10, due to ties in 2006, 2007, and 2013), only 2 of them had a losing record in spring training. On the flip side, over those same ten years, the 10 teams that finished with MLB's worst regular-season record ALL had a losing record in spring training.
Two years ago, Lewie Pollis at Beyond the Box Score did a more involved study, featuring every MLB team from 2007 to 2011. For the 150 teams covered in that study, he found a positive correlation of .325 between spring training and the regular season, with a coefficient of .105, which means ~11% of a team's performance is reflected in how it does in spring training. Not a massive connection, but a connection.
On an individual level, the Tribe's top performer of spring was definitely Michael Brantley. He put up a batting line of .500/.552/.740 in 58 plate appearances, with 10 extra-base hits. Other with an OPS better than .900 in 30+ were Ryan Raburn (1.071), Jason Kipnis (1.000), Elliot Johnson (.973), Asdrubal Cabrera (.955), Lonnie Chisenhall (.918), Nick Swisher (.906), and Matt Carson (.905).
On the opposite end of thing, Michael Bourn's line (before being shut down with a hamstring injury) was just .214/.267/.214. Others with an OPS below .700 in 30+ PA were David Murphy (.581), Nyjer Morgan (.625), David Adams (.655), and Carlos Santana (.697).
For better or for worse though, there's very, very little correlation between spring training and the regular season for most individual numbers. The ones that have the strong connection are walk rate and strikeout rate. Raburn, Mike Aviles, Bourn, Johnson, and Yan Gomes posted low walk rates; Santana, Swisher, Cabrera, Kipnis, and Morgan posted the highest walk rate. Chisenhall was at 10%, which is roughly average, but a big boost over his regular season figure.
Brantley struck out just twice in 50 at bats, as he continues to have some of the finest bat control in baseball. Murphy and Cabrera also had low strikeout rates. Gomes, Bourn, Johnson, and Swisher posted the highest strikeout rates.
Those same metrics (strikeout and walk rates) are even more significant for pitchers (while ERA has nearly zero correlation). Here are the K/9 and BB/9 for those pitchers most likely to start more than a game or two:
There's more good than bad there for the Indians, though McAllister's numbers should be of some concern, and perhaps Salazar's too.
Here are those same figures for the 8 relievers who've been named to the Opening Day roster:
Keep in mind that the ample sizes there are very small. That said, lots of nice strikeout rates there, with three walk rates higher than you'd like to see. I didn't think a whole lot of it when Atchison was signed earlier this offseason, but he certainly pitched well in the Cactus League, and he earned his spot on the roster.
Anyway, with this, we close the books on spring training. Tomorrow brings the first game that counts, hopefully with 175 to 180 more to follow.