John Isner leads their previous meetings 4-3. Johnson has won their last 2. The most recent was in January in Auckland and Johnson won in a third set tie break. In July last year on a hard court in Washington Johnson won in 2 tie breaks.
Isner has only played in Acapulco twice and lost in the first round both times. Those matches were in 2014 and 2010. In 2014 he lost as favourite in 2 tie breaks to
Johnson has won 1 of his 2 matches in Acapulco. He lost in 2 tight sets last year to Dolgopolov.
Stats this year don’t really favour either player so we have some value on Johnson as underdog. Obviously with 2 big servers we have the option of backing servers.
I think we get 3 sets.