Does this river bluff work 2/3 the time??

[ur2barredout]

I made the isolation raise because the guy had been limping in early pos a lot. Board is kinda coordinated on the flop to cbet into two. I bet the turn and the guy called very quickly. Thoughts
Full Tilt Poker, NL Hold'em Tournament, $16,000 Guarantee (Rebuy), 200/400 Blinds, 50 Ante, 9 Players
LegoPoker Hand History Converter

BTN: 10,269
SB: 6,270
BB: 18,905
UTG: 43,633
UTG+1: 40,575
UTG+2: 25,082
Hero (MP1): 49,105
MP2: 19,849
CO: 37,922

Pre-Flop: (1,050) 9 [img]/images/graemlins/spade.gif[/img] J [img]/images/graemlins/spade.gif[/img] dealt to Hero (MP1)
UTG folds, UTG+1 calls 400, UTG+2 folds, Hero raises to 1,600, MP2 folds, CO calls 1,600, BTN folds, UTG+1 calls 1,200

Flop: (5,850) [img]/images/graemlins/spade.gif[/img]5 [img]/images/graemlins/diamond.gif[/img]6 [img]/images/graemlins/heart.gif[/img]3 (3 Players)
UTG+1 checks, Hero checks, CO checks

Turn: (5,850) [img]/images/graemlins/spade.gif[/img]A (3 Players)
UTG+1 checks, Hero bets 4,400, CO calls 4,400, UTG+1 folds

River: (14,650) [img]/images/graemlins/diamond.gif[/img]2 (2 Players)
Hero bets 43,055 and is All-In,