David Wallace breaks tackles, and Jason White obliterates ball carriers - so someone's reputation had to give when the pair collided in the early throes of Ireland's Six Nations Championship match at Lansdowne Road last weekend.

Primed with latent aggression, White exploded from the Scottish defensive line only to be left groggy and on the seat of his pants, a cartoon caricature minus the halo of birdies, as the Irishman careered into the open spaces. As a snapshot it offered a confirmation of Wallace's ability.

White tackles with the ferocity of an enraged rhinoceros - just ask Jerry Flannery - so to escape his clutches following a bone-on-bone collision is a cause for relief as much as celebration. Wallace smiles when prompted about the encounter, his modesty disarming.

"I suppose he hit a bony part of my hip, good child-bearings hips that they are. I was lucky where he hit. I knew that there was a big, blue shirt coming, but that was the extent of it. I just turned the hip into him and I managed to get away with it."

So the self-preservation instinct takes over? "Definitely," he laughs. "If you run a straight line then you are making it easy for the tackler. You have to make them feel a little uneasy, because if you do it once then they're less likely to try and smash you the next time, because they're not sure which way you're going to step.

"The ball-carrying side of things usually goes alright, but there are other parts that I needed to concentrate on, and those are now up there with the ball-carrying, which has made me happy."

Wallace's footwork and intuitive radar that allows him to escape cluttered corridors intact makes him the most effective ball-carrier in Irish rugby since Victor Costello.

It's not just about brawn, though, as he possesses the speed and athleticism that make him an elusive target for any would-be tackler. He excelled against the Scots, but conceded that there was one moment that irked him when Scott Murray ripped the ball from his grasp.

"I was very annoyed with myself for that, for two reasons. It wasn't really part of the pattern that we were trying to play, and it was down to me trying to get myself more into the game in terms of ball-carrying.

"Secondly, it was a bad idea, poorly executed. The ball was greasy and he got a better grip on it. I was trying to hold on to it for a while, knowing that he had a better grip and there were two or three seconds where I knew what the eventual outcome would be but was powerless to prevent it."

The Garryowen and Munster flanker is enjoying his rugby, particularly after his travails last season.

"It's going a lot better than it was last season, although I was happy with the way things went towards the end of last season.

"It's weird to say it, but it was only an injury to Denis Leamy last year and to Alan Quinlan that gave me chances. It's just trying to grab it when you can. Back at the start of last season, for six months, it was very tough not playing much professional rugby (he spent a lot of time with Garryowen). I came into this season not wanting a repeat of that, and from the very start I tried to put everything into it.

"There was a stage when I wasn't picked for the first Heineken Cup match and I was disappointed with that. I'm happy that when I did come in, it went well for me. I've been talking to coaches, getting feedback on what parts of my game I need to concentrate on."

He's obviously absorbed the lessons diligently.

"When I first came in I was a little bit in awe of everything. I had it up there on a pedestal, the whole experience. (I'm) enjoying it a lot more being here and just feel a lot more comfortable in the environment going out playing. When you're younger, you always have a second chance. The older you get, you realise you have to grasp it with both hands and hang on."

There's nowhere he'd rather be tomorrow than Twickenham, although he smiles at the suggestion that Ireland's task will be made easier given the number of changes England coach Andy Robinson made.

"It doesn't always follow, and half the time it can serve to lift a group of players. About 80 per cent of preparing for this match is focusing on ourselves rather than the opposition. If we don't do the work, then it doesn't matter what they do."

If Ireland are to prevail, Wallace will have a pivotal role.