Ordinarily, you could argue that it is too early to spot any World Cup trends after a single gameweek.But this is a summer like no other. An expanded tournament of 48 teams means more games, more action, and more data to pore over. With 24 games played after the first round of games, we have already seen over one-third of the total fixtures played in previous iterations of the competition.Perhaps it is better to call them quirks rather than patterns, but The Athletic has opened up its data and tactics notebook to share some observations that have caught the eye after the first round of fixtures.Let’s dive in.Do hydration breaks kill momentum?Run from it, dread it, the FIFA Powerade hydration break arrives all the same.Announced over a booming tannoy, the three-minute stoppages ostensibly exist to cool players down yet have become one of the tournament’s most heated talking points.On the tactical front, many argue that the breaks halt the momentum of dominant teams and alter the rhythm of matches.Momentum is hard to define. It is usually some heady cocktail of territorial dominance, sustained pressure and chance creation. The Athletic attempts to distil this subjective alchemy into a precise formula using our gameflow charts.The charts blend expected threat — the change in goal probability associated with each pass — with expected goals in three-minute windows to show which side is on top. To stop a single big chance from skewing the picture, xG is capped at 0.2.An example below shows the gameflow chart from Australia’s 2-0 win over Turkey. Both goals came just after hydration breaks, with the second in particular arriving after a sustained spell of Turkish dominance prior to the interruption.Curacao are another team who can feel aggrieved. Their first-half hydration break came just after they had equalised against Germany and while they were causing the heavy favourites uncomfortable problems. But looking at their overwhelming dominance over the course of the match, it is hard to argue that Germany would not have wrestled back control anyway in normal circumstances.Beyond a few cherry-picked examples, it is almost impossible to prove that hydration breaks systematically alter events beyond the natural ebbs and flows built into the sport. Looking at the 10 minutes before and after each stoppage, only 14 of the 40 hydration breaks have seen momentum change hands.