What if Jean Van de Velde hadn't chopped his third shot into the Barry Burn at Carnoustie in 1999? Or if heavy rain had not forced Niki Lauda to retire from the 1976 Japanese Grand Prix, allowing James Hunt to snatch the title? In football, the name Rob Rensenbrink immediately sparks the question in the mind of anyone over 40: what if that shot hadn't rebounded off the post?
Rensenbrink's shot at glory came in the 1978 World Cup final in Buenos Aires, as part of the Netherlands' legendary "Total Football" team. In a stadium packed with 71,000 Argentines, speckled with a few hundred Dutch supporters, substitute Dick Nanninga scored a late equaliser to cancel out Mario Kempes' early goal for the hosts. Then came Rensenbrink's moment. As the clock ticked past 90 minutes, the sweeper Ruud Krol hoisted a free-kick from the centre circle towards the edge of the six-yard box.
Rensenbrink drifted in from the left, stuck out a boot and steered the ball beyond the goalkeeper Ubaldo Fillol. The world held its breath - and the ball pinged back off the post, to be lashed away by a defender. In extra time, Kempes struck again, Daniel Bertoni added a third and the rest is history.
At his home in Oostzaan, a commuter town to the north of Amsterdam, the 67-year-old Rensenbrink is remarkably sanguine about what might have been. "Of course it's engraved in my memory," he says. "It'll be there until my dying day. It was an impossible angle, and yet it hit the post. It could just as well have gone in. It wasn't even a shot; it was a touch. I didn't have room to shoot. I just placed it. And it could just as easily have fallen to a team-mate to tuck away, but it wasn't to be. But I don't reproach myself that it didn't go in, because it wasn't a real chance."
Had Rensenbrink scored, and the Dutch held on, he, rather than Kempes, would have finished the tournament as top scorer. Remarkably, four of his five goals came from the penalty spot, including the opener in the 3-2 defeat by Scotland that enabled the Dutch to edge through on goal difference. "We were lucky in the first round against Scotland," he says. "The Scots went 3-1 up with around a quarter of an hour to play and we were worried it would be 4-1. If they scored one more goal, we'd be going home. And then Johnny Rep scored from 25 yards into the top corner."
There are other reasons to ponder what might have happened had Rensenbrink's shot gone in. The 1978 tournament was hosted by General Galtieri's murderous regime, and many observers believed the junta was determined to engineer a home win at any cost. Had the Dutch gone 2-1 ahead, would they have somehow been denied victory? Rensenbrink doesn't think so: "If that ball had gone in, there were only two minutes left; Argentina wouldn't have won," he says. "But I have my question marks: we were set to play the final against Brazil unless Argentina could beat Peru by six goals. And they did it. Something must have happened, because we only managed a 0-0 draw against Peru. They were a good team."
It wasn't the only dubious moment: the start of the final was delayed because the Italian referee objected to a wrist support that the Dutch midfielder Rene van de Kerkhof had been wearing since the opening match against Iran. The Dutch players threatened to walk off the pitch, until the officials compromised and let Van de Kerkhof back on with a different strapping. "He'd worn it throughout the tournament and then suddenly the referee comes along," says Rensenbrink. Yet he dismisses the idea that the Dutch players were unsettled by dirty tricks. "As a player you don't have that feeling; you go out on to the pitch to win and play well. It's only afterwards that you look back and think about it."
Rensenbrink also faced Argentina in the 1974 World Cup, a 4-0 demolition job that featured two goals by Johan Cruyff. "The team of '74 was the best I played in," he said. "Full of top players: Cruyff, Neeskens, Krol, Rep, Van Hanegem."
Rensenbrink came into the reckoning relatively late, mainly because he played in the Belgian league with Anderlecht. Having made his international debut against Scotland as a 20-year-old in 1968 - a 0-0 draw in Amsterdam - he went nearly four years without a cap until he caught the eye of Rinus Michels in a pre-season game against Barcelona. "It was a stroke of luck for me, because we won 2-1 and I scored. Michels was coach of Barcelona, and when he became the national team manager he called me up. All because of that one friendly match."
Rensenbrink was a prolific scorer in Belgium, his mazy dribbles earning him the nickname slangenmens, or "snake-man". He established himself as the first choice on the left wing, with Cruyff playing in the centre. "We were all good footballers," he says. "We didn't look up to each other. People compared me to Cruyff, but I was a different type of player: more technical, more of a dribbler. I never thought of myself as a lesser player than Cruyff."
Rensenbrink has been impressed with Louis van Gaal's team. "I didn't expect them to reach the semi-finals. But from what I've seen so far, they're a solid team. Defensive, but strong. And they need those moments from [Arjen] Robben. Things always happen when he's on the ball.
"I don't think Argentina have played spectacularly well. And it's a pity for them that [Angel] Di Maria is injured; he's been a good player. [Lionel] Messi has had his fleeting moments, but he hasn't put his stamp on the team. Although he scored that fantastic free-kick into the corner, so he can make the difference. We'll see."
And his tip for the title? "Germany are a strong team. I think they'll beat Brazil and face Netherlands in the final."
Rensenbrink played only once in Scotland, a UEFA Cup-tie against Dundee United in 1979 which the Tannadice side won through Frank Kopel's late goal in the away leg. But he belongs to a generation when Scots were still regarded as world-class footballers. "Celtic had a player out on the right wing, this little guy . . ." he recalls. "Jimmy Johnstone?" I interject. Rensenbrink leans back and smiles. "Yeah," he says. "Now that was a player."