Before the voters used to just pick one person they wanted to win. So you could get a situation where some voted for Purdy, while others voted for CMC. That would split the vote, and possibly allow a third candidate (Josh Allen, wooo!) to win.
Now the voters pick their top 5 MVPs ranked in order, and they get points based on where they ranked them. 5 points for ranking first, 4 points for ranking second and so on. The player with the most points gets MVP.
So a voter could put Purdy #1 and CMC #2, and another voter could put CMC #1 and Purdy #2 and it's likely one of them would still win if enough people voted like that.
Some people think that is how all elections should work, because it would allow third party candidates or more minor candidates within the party a chance to actually win. If a Democrat didn't like Biden, they could vote for whichever candidate in their party they liked most and wouldn't feel like they were "throwing away" their vote, because they could still rank Biden second or third on their ballot.