It is a manager's worst nightmare to see a tactical innovation of theirs fail. Marcelo Bielsa is not immune to such occurrences, he like many other top coaches have faltered at various junctures in their careers.
Hardly likely to be a pivotal game in the grand scheme of things, Bielsa's Brighton defeat was one of those days, where the tactics misfired.
From the beginning at Elland Road, Leeds utilised Raphinha on the left wing, and Jack Harrison on the right. Typically, the wide duo are the opposite way around.
Both players are naturally left-footed so Bielsa's thinking may have convinced him that swapping the pair would not have a negative impact on the way the team played, but that was not the case.
Some of Raphinha's best moments in a Leeds shirt have come directly from his out-to-in runs across the face of the opposition penalty area.
In fact, both of his Whites goals to date have been scored in this way, taking up a central position after drifting in from the right against Everton, and a magnificent dribble and finish down the right versus West Brom.
Jack Harrison and Luke Ayling's partnership is a particularly unique one too. One of Leeds' most frequently-used passes is Ayling's long diagonal from right-back to Harrison on the left wing.
It has become almost like muscle memory for both players now, Ayling pumping the ball forward with the same precision and weighting each time, and Harrison either taking the ball down on his chest or at his feet before driving forwards.
Although Raphinha can play on the left, that relationship is not quite as refined between he and Ayling as it is with Harrison, who has been the 29-year-old defender's 'diagonals partner' for the past three seasons.
Between them, Harrison and Raphinha had five touches inside Brighton's penalty box, the Brazilian registering none of those, in fact.
Against West Bromwich Albion, the pair touched the ball nine times in the opposition penalty area, and at home to Newcastle, a combined 13.
The likely thinking behind Bielsa's wing experiment was sound, though. It was not thought-up hours before kick-off on a whim.
Brighton had utilised an unbalanced back-five in many of their games this season, with Solly March - a winger - on the left, and Joel Veltman - a centre-back - on the right.
These opposing wing-backs in Brighton's system hardly share too many similarities. To contend with March's attacking, Bielsa may have asked Harrison to slot in on the right instead, owing to his superior height and build.
Equally, Raphinha could - in theory - have caused Veltman more problems by driving inside as he usually does, opening space down the left for Gjanni Alioski to overlap.
In truth, these alterations did not bear fruit and the plan failed as Leeds were beaten, restricted to seven poor quality shots.
Fortunately for Leeds, and the two wingers, if Bielsa's decision to switch the wide-men was a reaction to Brighton's peculiar wing-back pairing, it is unlikely we will see something of a similar nature much more this season.
Nevertheless, Bielsa is an astute tactical operator, and will have pored over the game's passages of play since the final whistle blew. He will have recognised this weakness of his tweaked system, and will be likely to learn from that mistake.
