Wins and losses at this level are often decided by the width of a crossbar or the length of a through-pass.
Or a simple hunch when it comes to finalizing the lineup.
Germany coach Joachim Loew aced his first real test of these European championship Saturday, putting his neck on the line by picking inconsistent forward Mario Gomez over German legend Miroslav Klose to lead the attack in the opening game against Portugal.
And Gomez, who enjoyed an outstanding 40-goal season with Bayern Munich, repaid that decision in spades with the only goal just as Loew was preparing to take him off for birthday boy Klose.
Hindsight is 20:20 of course, but had Germany failed against Portugal - who hit the crossbar twice - there would have been an in-depth inquest into the decision to leave Klose on the bench. Though recovering from an ankle injury - from which he is fully recovered - Klose boasts one of the best strike rates in the history of soccer with 63 goals in 114 games. He is five goals away from tying Gerd Mueller's national team scoring record and his 14 goals at the World Cup finals are tied for second most in history, alongside Mueller.
If that wasn't enough, the Germans have never lost a game in which Klose scored. That streak now spans 40 games - 36 of which have been victories - and the Lazio man has also led the Germans to the final of both the World Cup and the European championship, although he has yet to taste ultimate victory in either tournament.
Gomez, on the other hand, is a poor man's version of Klose in the eyes of the German public. Though both are good in the air - it was a header that gave Germany a 1-0 win Saturday - Gomez has been less than reliable, particularly in pressure-filled games.
The Bayern frontman enjoyed a sterling campaign for the most part last year, especially in helping his club to the Champions League final. Gomez scored 12 goals in 11 Champions League games - including a four-goal outing against Basel and another three against Napoli in the knockout rounds - but was one of the principal reasons that Chelsea took the trophy on penalties, failing to convert over 120 minutes despite having five attempts on goal in last month's final.
Similarly he was unable to make an impact in Bayern's domestic rivalry with league and cup champion Borussia Dortmund, failing to score in either league meeting or in the 5-2 defeat in the cup final.
And despite a respectable strike rate at international level - now 23 goals in 53 games - Gomez is more known in his homeland for his failure to score into an open net from two yards in a Euro 2008 win over Austria.
But perhaps Saturday marks a fresh start. Despite nine appearances now, mostly as a substitute, Gomez's winner was his first goal in either a World Cup or European championship finals, and he could conceivably have had another before being replaced after 80 minutes.
And it also created another selection headache for Loew. If the German coach thought Saturday's selection was a head scratcher, just wait until he has to pick his lineup for Wednesday's crunch game with the Netherlands.