Michael O'Neill is happy to continue tinkering with Northern Ireland's formation as he wants adaptable systems to cause other countries problems at Euro 2016.
In the 1-1 draw with Wales in Cardiff on Thursday night, O'Neill switched from a first-half 3-5-2 to the 4-3-3 he preferred in a qualifying campaign which saw them finish top of the group.
The advantage of playing three centre-backs is that it allows O'Neill to include Jonny Evans, Gareth McAuley and Craig Cathcart in his starting line-up, although his side were more effective going forward after the break when striker Conor Washington was withdrawn and Evans reverted to the left side of a back four.
Rather than spending the final three friendlies settling on a fixed system he will deploy against Poland in Nice on June 12, O'Neill is prepared to alter the team's shape on an ad hoc basis.
Reflecting on the Wales game, he said: "We were a little bit disappointed that maybe we didn't have more of an attacking threat with that system.
"I think the two lads up front worked very hard. It's the first time they've played together and Kyle (Lafferty) hasn't played much football. There are mitigating factors in that.
"There's always comfort as a coach and a manager when you say you're going to change to four. We threw Jonny in at left-back and he doesn't bad an eyelid and we played in the 4-3-3 and are able to deal with it.
"It's exactly what we want. In the summer we are going to have to be flexible. Either system has strengths or weaknesses depending on how the game's going.
"The most important thing between now and the end of the summer is the players are able to adapt it and understand it very quickly and the game on Thursday night gave me a lot more confidence that that's the case."
One player who is imperative to the Northern Irish in either system is striker Lafferty, who played 81 minutes against the Welsh, despite totalling just 45 minutes combined all season for club side Norwich.
His situation in Norfolk had been a concern to his countrymen, but, after completing a loan switch to Birmingham earlier in the week, O'Neill hopes he will now be up to speed by the time they reach France.
"It's him up to him now to have an impact as well," the manager added.
"Birmingham have ambitions and something to play for. That being the case, if he is a contributing factor to them having a good finish to the season then he'll be in a better frame of mind when he comes away with us in the summer."