Crusaders' dominance over the Blues in Super Rugby Pacific has extended to 17 wins in 18 games after Saturday's 15-3 win in Christchurch.
Lineout issues came back to haunt the Blues in the manner of last year's grand final loss, also to the Crusaders and coach Scott Roberton praised the role of his captain Scott Barrett.
"Scott Barrett's captaincy was incredible," Robertson told SKY Sport.
"Thirteen [first-half] lineouts, and he threw all the variations at them. At half-time, he was composed. He knew what we had and hadn't used and what we were going to do in the second.
"We wanted to make them tackle, and they did.
"The breakdown was where we won lots of little races. We didn't allow them to get access to our ball."
Blues coach Leon MacDonald saw his lineout come under pressure again, something exacerbated by the season-ending broken forearm suffered by lock Sam Darry.
"It's an area that has been an Achilles heel, but with Sam [Darry] in particular, he's done a really good job in that space. We need somebody to step up and take the reins.
"We're doing a lot of good work in that space, but we weren't quite right; a couple where the throws weren't quite right, or we didn't quite get the calling right. It's an area that's got to be good if you're going to win the title at the end of the year."
The Blues kicking game also came unstuck when the Crusaders dominated so much of the early possession and controlled the breakdown.
"We were probably kicking a little bit earlier, and not on the terms we wanted. We have got weapons in the back, and we wanted to use them."
Conditions were favourable to use the ball, and being unable to make the most of them was frustrating.
MacDonald said the side was in the race for a home playoff berth.
"We've got a little run home that's going to give us an opportunity to make the playoffs, and once you're in the playoffs, it's all go, so there's still plenty to play for."