Perhaps I should have said that being the best player, as determined by the stats, WAR in particular, does not necessarily mean being the most valuable player. If Wright were to have a season ending injury, would that hurt the team's season outlook more than if Bogaerts or Papi were to have a season ending injury? IMO, it's a tough call, even though Bogaerts is the clear winner by WAR.
There are intangibles and 'indirect effects' that others have mentioned, such as mentoring teammates and saving the BP, that are quite valuable that don't show up in the stats.
Also, there have been players with MVP type numbers in the past who have missed considerable time due to injury, and their teams didn't miss a beat while they were out. That begs the question about how valuable they really were.
This is not meant to say that Bogaerts is not the MVP so far. As I posted earlier, there are several names that could be mentioned and I really couldn't argue against them.