Okay, let me first state that I have never been a fan of Ryan O'Byrne. However, I never tire of explaining why he wasn't an asset to Montreal.
Ryan O'Byrne is really tall. You know who else is really tall? Jamie Oleksiak. I bet you haven't heard of him. He's a defenceman for Dallas at 6'7". But you have heard of Ryan O'Byrne and that's because he played for Montreal, even though they are pretty much the same hockey player. But O'Byrne seems to be this name many Canadiens fans cry over losing? Why?
Because he's tall. That's it.
Was O'Byrne skilled? Not really. He made errors in his own zone all of the time. More errors in fact than Mike Komisarek, yet very few bring up bringing him back into the fold (because he was overrated and got paid for being overrated. O'Byrne doesn't even have that notoriety). No, O'Byrne is known for scoring a goal on Montreal when playing the Islanders. A feat he repeated in Colorado against the Florida Panthers.
"But O'Byrne once rocked Chara and he fights!"
O'Byrne is also the fifth defenceman on the Avalanche, who balance their defenceman's minutes and are known to having one of the worst D units in the league. Despite not seeing as much ice time as Erik Johnson he has the same amount of giveaways with eight. Last season, Jan Hejda and Ryan O'Byrne were scored on the most when playing PK for the Avalanche.
In other words, O'Byrne plays what appears to be good minutes but he plays it against the softest competition. On any other team, the coach would use O'Byrne more sparingly. This is the cause for most "big dumb strong" players. Nobody was afraid of O'Byrne. He isn't much of a fighter, he shakes the opponent more than anything and he's too slow to swing. He had several inches on Brad Stuart and in a retaliation/instigator after a clean hit on Landeskog, O'Byrne had to tussle him down as his retribution. Did it send a message? Not really. O'Byrne sat in the box the same way Ryan White did, watching San Jose score two goals on his penalty. No lesson taught.
But Ryan O'Byrne is big. And Canadiens fans have an inferiority complex. So how dare they trade their biggest player for Bournival.