I had a nice experience with this tactic
(79016935). It's not the first time I use box+1 succesfully but I believe this is a really good example of what it does and when to use it.
I knew I had to guard my rival's key player no mather what (L. Zaccaría
(27292670), Argentina's NT PF) because the other ones were not as good as him, and it worked like a charm. My stating defender quickly made 3 fouls but the bench player did an outstanding defensive job.
He was attampting 11-19 FGs and 26 Pts on average before the match. The result was him attempting only 8 FGs in the whole match, with just 12 Pts.
I think the key to this tactic is to use it when you know you are facing an unbalanced offense with only one key player. If there is more than one good offensive player to guard it won't work because what you are going to get is a zone defense with your best defender never being in the equation to guard those other shooters. Well, at least that's the way I see it :)