Gatland coached Ireland from 1998 to 2001 but cemented his world status in a trophy-laden spell guiding Wasps to English and European dominance between 2002 and 2005.

Ireland face Gatland's Wales in Cardiff on Saturday, where victory would all-but sew up the RBS 6 Nations title and keep Schmidt's men on course for the Grand Slam.

Captain O'Connell admitted Ireland's top stars still strive to pick up ideas from the Wales boss, especially during the 2009 and 2013 British and Irish Lions tours that Gatland spearheaded.

"I think he's an incredible coach: for as long as I can remember we've being trying to poach ideas from Warren Gatland," said O'Connell.

"We played Wasps with Munster in 2003 or 2004 and they were so far ahead of anything any provincial or club side were doing.

"It was a rude awakening for that day with Munster.

"It was the same when we were on the Lions in 2009.

"We tried to bring so many of the things that he had in the set-up there back to Ireland and back to Munster.

"His record is incredible, it speaks for itself.

"He's a terrific coach, a great guy, a very clever coach, and kind of like Joe, they are both a little bit ahead of their time."

Word-perfect skipper O'Connell is increasingly the master of pre-match praise, designed to remove any unnecessary sting from pivotal Test contests.

In the autumn O'Connell lauded Springbok lock Victor Matfield as the best lineout opponent he had ever faced - then promptly dismantled the veteran second-row's set-piece work in Ireland's 29-15 victory over South Africa in Dublin.

The seven-cap Lions second row then hailed Stuart Lancaster's class of 2015 as the best England side he had ever known in his career - only to drive Ireland to a convincing 19-9 triumph in Dublin.

There can be no doubting O'Connell's sincerity, but behind the flattery Ireland scheme relentlessly on ways to deconstruct their opponent's strengths.

"They're similar in terms of being ahead of their time," said O'Connell when asked if Schmidt and Gatland are cut from the same cloth.

"They've different ways of going about things but one of the big things both of them do is they make what seems complicated very simple.

"When you're playing an 80-minute rugby match I think players are generally exhausted or close to exhausted when they're playing and the simpler you can make things the easier it is to be good at it, the easier it is to be aggressive at it.

"I think Warren probably pioneered that way of thinking.

"But they're very similar in that they're just ahead of the game all of the time."