Hearns was a nightmare to box from the outside. Hagler fought a brilliant fight and put on one of the best displays ever of a boxer changing from one's original style. Obviously guys like Whitaker and Mayweather were difficult to outbox. That's a huge understatement
Hearns was hard to box from the outside because of his reach and speed. Floyd and Sweet Pea were hard to outbox because of their skills and ring IQ. Also, Hearns had an excellent jab.
No he didn't lol, nothing much happened in that round and either man could take it, depending on whether you liked the head shots that Sillakh landed (of which there weren't many) or the jabs that Kovalev was landing to the body. I mean sure, Sillakh looked "cuter" in the ring with his bouncy footwork and circling but he wasn't boxing effectively, in the end he got timed and knocked out by a counter right (his dumb boxing was actually his demise). I and many other people actually gave the round to Kovalev, he didn't outbox Kovalev at all.
Well hardest indicates the most difficult to win rounds against by trying to outbox them, not hardest to win rounds against, and Mayweather and Whitaker definitely take the cake if we're discussing that criteria.
Mayweather, Ward, Rigondeaux, Lomo (with more experience) Past 15-20 years you can add Jones and Whitaker.
Why "LOL", who outboxed him? lol that statement is ridiculous. Regardless of who won the round, name a single fighter that hasn't lost one?