The xG per possession with fewer than four passes has dropped from 2.7 xG per 100 possessions to 0.7 xG per 100 possessions. In other words, possessions with fewer than four passes under Armas have been one fourth as valuable. At the same time, an increased value of long possessions has been canceled out by their decreased frequency.

Basically, they’re doing a lot more of the stuff that they’re not good at, and they are doing less of the stuff they are good at.

And here comes Armas' worst nightmare: the Red Bulls' performance has plummeted even though their gameplay has been largely consistent with a lot of Armas' tweaks. They have enjoyed a recent nice run of results, but their underlying performance paints a different picture. Their offense has collapsed; they create only 1.21 xG per game for this season, 0.7 xG less than last season, a 36% decrease.

The defense also suffers; their xG against per game increased from 1.31 last year to 1.44 this year. Armas often talks about how New York aren't closing down their opponent quickly enough: this year, in the open play, the Red Bulls have allowed their opponent to control the ball 12.5 seconds per possession, 0.8 seconds more than they did last year (P < 1x10-10, Welch's t-test).

Putting a stamp on the team is one thing, improving it is another. The Red Bulls haven’t been able to transition from the idea into the performance. What has gone wrong?

Replacing Adams

One big issue for Armas needed to address before this season was the midfield namely, a replacement for Tyler Adams. Adams and Sean Davis made a formidable pair last year. Replacing Adams is tough, but Marc Rzatkowski had been groomed for almost a year. Defensively, Adams averaged 11% of the team's total number of tackles in the midfield when he started, the top 40th percentile for the qualified central midfielders since 2016. His tackle (50%) and header success (60%) were both within the top 35th percentile. But Rzatkowski is physically inferior to Adams. His tackle (31%) and header success (44%) currently sit in the bottom 35th percentile. Still, he is aggressive and he doubles Adams' total tackle attempts. Overall, the Red Bulls have essentially been able to replace Adams' defensive contribution.

But the offense has suffered without Adams; in open play, Adams contributed 15.3% of total expected buildup (xB - the sum of xG when the player doesn’t take the final shot or make the final pass) when he started in the central midfield last season (top 13% percentile since 2016). Rzatkowski hasn’t been able to fully replace Adams' output, amassing 13.3% total xB (the top 31% percentile since 2016). But Davis has filled that void, increasing his xB% from 10.7 to 15.7, a 44% increase. But there is a catch; Davis is also using 13.4% of the total number of passes, a 20% increase from last season. Davis' increased output (by xB%) comes largely from his increased usage.

Armas might have given Davis free reign to replace Adams’ output because of Davis' potential, but evidence also points to some other solutions; first, Rzatkowski uses only 8.8% of the total passes but creates 13.3% of the total xB. The same also applies to Cristian Casseres Jr; he produces 10.6% of the total xB with only 9.5% of the total passes. Both players seem to be creating chances better than Davis does.

Second, Davis' participation doesn't improve the quality of the possession. Looking at all the open play possessions that start in the defensive third, Davis' involvement this season increases the xG per possession by 49%, sitting in the bottom 43th percentile among all central midfielders since 2016. His performance here has already been a massive improvement from last season, when his involvement decreased the xG per possession by 17%. However, Rzatkowski and Casseres Jr. vastly outperform Davis in this metric, with a 350% and a 400% improvement of their xG per possession, respectively. Their numbers are better than 97% of all central midfielders since 2016. Giving them more responsibility in the offense phase is something Armas should consider if he wants to improve the offense.

Lost in Transition

Putting aside the across-the-board drop in offense from 2018 to 2019, the starkest difference is that the Red Bulls’ attack suddenly dives between the 15th and 30th minute of the game: