I know how much you missed these self-explanatory Guardian Chalkboards, even if you don't.
Liverpool were outstanding in the first half on Saturday, unlucky to not be ahead by more than a solitary goal. But Sunderland regrouped, better in the second frame, and reaped the reward.
The first example of that regression was where Liverpool won the ball (when they actually did). Liverpool pressed furiously in the first half, reclaiming possession with ground tackles and interceptions much higher up the pitch.
After the restart, Liverpool won fewer ground tackles, all in their own half, with interceptions coming closer and closer to Liverpool's goal. The home side simply lost that territorial battle in the second half. They were unable to press as effectively, probably due to fitness levels, and increasingly defended deeper as confidence plummeted, while Sunderland grew in stature and belief.
In fact, Liverpool won half as many total duels in the second half: 28 to 14 – seven fewer aerial duels, five fewer ground tackles, and two fewer take-ons. The fight for aerial supremacy was another conspicuous reversion, especially since Liverpool became more and more predisposed to hopeful punts in the general direction of Sunderland's goal.
16 won, two lost in the first half; nine won, seven lost in the second. Carroll won half as many after the interval (six compared to three), while Kuyt didn't win a single aerial duel after coming on (three unsuccessful).
Meanwhile, Sunderland's pattern of play was pretty much the polar opposite. The Mackems made more successful tackles in the second half with far fewer unsuccessful, and made their inceptions and tackles in more threatening areas.
Liverpool's passing followed a similar shambling script – more successful and composed in the first half, more erratic in the second.
Liverpool attempted 38 fewer passes in the second half, but had nine more unsuccessful. The first half completion percentage was 79.3%; it dropped to 73.0% in the second. There was almost a coherent pattern in the first 45: playing from the back to the flanks, then up the flanks into the final third. Comparatively, the second half is a hodgepodge of desperate long arrows – many, many more in red – beginning in Liverpool's end and ending without finding a target. The heatmap shows how Liverpool were more bogged down in the middle of the field after the interval, pushed back toward their own goal with next to no passes in the opposition's penalty box.
Sunderland's passing wasn't dramatically better in the final 45 minutes – attempting and completing comparable totals – but the chalkboard demonstrates how they attacked Liverpool's fullbacks much more directly, especially Flanagan on the right. Far more passes into the box came from that flank following halftime. Far more passes into the box came in general.
I don't mean to suggest that Steve Bruce waved a magic wand around his enormous noggin during the half-time team talk, while Dalglish et al rested on laurels sipping tea, but there's a reason the "tale of two halves" cliché persists.
Liverpool were notably worse in multiple areas as the game went on, and Sunderland took advantage. It's one thing when that happens in the first game, with only three starters who featured in the first game of last season and four players making their debuts. But tolerance and understanding will only last so long when we've seen much of the same during the previous two campaigns.