Nine times out of 10, when a goalkeeper commits an error, it costs his side a goal. It's a risk that comes with the territory.
Everyone will have their most memorable gaffe from the men with the gloves during the Premier League era. Some will pick out Shay Given at Coventry City, while others would plump for Jerzy Dudek, who gift-wrapped a goal for Diego Forlan.
And who can forget Massimo Taibi's blunder at Old Trafford against Southampton? Unsurprisingly, the Italian did not last much longer at Manchester United.
Supporters of rivals Birmingham City and Aston Villa, though, will probably first recall the night in which goalkeeper Peter Enckelman made the mistake that has seen him go down in 'Second City Derby' folklore.
For the first time since 1993, newly-promoted Birmingham took on neighbours Villa at St Andrew's 12 years ago today. The belief heading into the encounter was that Enckelman's Villa would claim the bragging rights.
However, from the first whistle, it was clear that Steve Bruce's Birmingham were determined to defy the doubters.
They did just that in the 31st minute when Republic of Ireland international Clinton Morrison stretched to break the deadlock from seven yards out.
Yet, with 13 minutes remaining, Enckelman ensured that his side's chances of getting back into the game were over. Olof Mellberg took a thrown-in from the right touchline, which appeared to be innocuously rolling towards the Finnish keeper.
The ball rolled under his foot and by the time that he had turned to retrieve the situation, it had nestled in the far corner of the net, with referee David Elleray having adjudged that the ball had skimmed Enckelman's boot, meaning that a goal was given.
Substitute Geoff Horsfield compounded Enckelman and Villa's misery in the 83rd minute when he scored a third and final goal for the hosts.
Speaking after the final whistle, the Villa stopper said: "I haven't got a clue whether or not I touched the ball. I'm pretty sure I missed the ball completely, but I was not sure of the rules and just presumed it would be a goal whatever."
BIRMINGHAM: Vaesen; Kenna, Purse, Cunningham, Grainger; Devlin (Powell), Savage (Hughes), Cisse, D Johnson; John, Morrison (Horsfield)
VILLA: Enckelman; Staunton, Mellberg, Alpay, De la Cruz; Kinsella, Johnsen, Barry, Samuel; Allback (Dublin), Angel (Vassell)