Walter Smith should know. A man embroiled in the highs and lows of the high-octane contests in his previous incarnation as Rangers manager, back at the helm, he admits he is older and wiser but no more capable of keeping the feelings in check.

In the build-up, throughout the match and even in the aftermath. The sensations are the same. Well, he assumes they are. The preludes are just as tense, the matches still as draining and the taste of victory definitely as sweet. But he can't compare the despondency of defeat just yet. In his one and only Old Firm match since his return to the Ibrox managerial post, his side triumphed 1-0 at Celtic Park and he hopes he will remain in the dark about those feelings of despair beyond Saturday, when the teams play out the final head-to-head of the current campaign.

Winning both match-ups with Gordon Strachan may not ease the pain of losing a league title, which in truth was already long-since out of his reach when he rejoined, but many believe it would give him the psychological edge ahead of next season and set down a marker.

For Smith, though, the personal incentive is not any more long-term than the ability to relax and savour his Saturday night without the company of the "what if" gremlins.

"When you go into an Old Firm game, never mind laying down a marker, you've just got to try to win. Whatever stage we are at, they do in many ways stand on their own. This one, on paper, looks as though it doesn't mean much and, for Celtic, it doesn't mean anything at all. But in saying that, although Celtic have won the Championship and are in a cup final, everybody who is there has been there long enough to know there's no respite. Everybody will be going into the game looking to win it and feeling motivated. But that's what I mean, whether it's the first game or the fourth game or a cup tie, it doesn't really matter what tournament it's in, it's Rangers v Celtic and it doesn't really mean anything other than when the two teams meet, you have to win."

Having watched from the sidelines as a supporter during his sabbatical as Rangers boss, he still became embroiled in the atmosphere, but says nothing compares to being in the midst of the mayhem. "If your team manage to win, aye, you miss being involved, but it's not so clever when you are on the losing end. It was strange to go back to watch the games [after having] that involvement - it's not the same. It didn't have the same edge to it as it obviously did when you were in the thick of things. There's nothing quite like it, especially in a game that's close and when the tension builds up an awful lot of the time."

After spell in England guiding Everton through Merseyside derbies, he subscribes to the theory that little can match the Glasgow version, not because the fans care more, but because there is usually more resting on the outcome than simple bragging rights.

"It is looked upon as the game in Scotland or, if you like, group of games, if you take it as four league games. They are the games that represent Scotland abroad a lot of the time and I think everybody down there appreciates the tension that rivalry brings.

"Down there it is different. Take Liverpool and Everton - you can't say the supporters there are any less passionate about wanting their team to win, that's not the case. It's just that, over the years, a lot of the time, Liverpool have been in the situation where they were looking at winning the league championship and Everton weren't, then Everton had a wee spell when they were good. But nearly every time Rangers and Celtic meet each other, the outcome actually means something. For example, when Rangers won the four games in the nine-in-a-row season it was a massive achievement, but each time you are not only directly up against your biggest rivals, but also your biggest threat to winning the championship and that's not always the case in other countries. In Scotland it invariably is."

It is a fear borne out by statistics. In the past 22 titles carved up between the Old Firm, there have only been three cases where one side has taken more points from the head-to-heads and not then also collected the league trophy.

Smith's ability to analyse the tribal get-together as an outsider looking in from his English vantage point allowed him to consider the merits of a slightly more detached approach but, back in the high-tension environment, like a soon-to-be-divorced couple, the cerebral and emotional struggle to co-habit.

"When you come back again, obviously experience in the game helps you. It's like every other aspect of life, if you go into it for the first time you will feel everything, you will feel really nervous. If you experience it and carry on, then you will still get those nerves. I think that's necessary and you would be a strange person if you didn't have nerves before those games, you still have that. You can try to remain reasonably calm, but the Old Firm game sometimes brings out the worst in you.

"You have a situation where all the players who play also have to handle what can be a volatile atmosphere. If you look back on the game, sometimes the foreign players, and I include English players in that, find it a wee bit difficult to handle the overall pressure involved in the game and that's been seen on a number of occasions, but that's only to be expected because of, normally, the importance of the game. I don't sign a player with the Old Firm in mind but at different times I have had players who would worry about going into that atmosphere, but they had to handle it. It is the same sometimes in the dugout - the emotion kind of runs away from you a bit in that game. Maybe not next week's because some of the edge has been taken off it since Celtic have won the Championship, but it's always there, just bubbling under the surface."

The Ugo Ehiogu winner in the March encounter gives him belief that another win is possible, but nothing can be assumed - which is why the triumphs taste all the sweeter.

"Fortunately, I have a few. We managed to win a few of the games the last time I was manager and I think one of the best was when Celtic moved back to Celtic Park and everybody was looking forward to the first Old Firm game there and we managed to win it. Although the atmosphere at the games is always good, I can remember that day, walking out and it was tremendous. I remember Tommy Burns telling me he had never experienced anything like the atmosphere in the new ground, because obviously they had played a few games in it before the Old Firm match, and he was right.

This time, it is at Ibrox and while there may not be enough at stake to see it eclipse those memories, being able to boast the better record in head-to-heads this term would give Rangers one positive from a campaign they will otherwise try to forget.