For the first time in a long while (perhaps since the start of the season!), Klopp varied his starting formation. Liverpool went 4-2-3-1 with Wijnaldum and Can as the midfielders, Oxlade-Chamberlain and Mané flanking Salah as the no. 10, behind Firmino as the striker.
While it proved effective, it wasn't clear why Klopp felt a need to switch up, since the same personnel could have easily fitted into his usual 4-3-3. But it felt like the defence was more solidly covered by two deeper-lying midfielders, rather than the more fluid system that would have seen them bombing ahead more often. Perhaps Klopp expected a more bruising battle in midfield, and so there was an advantage to shielding the defence a bit more strongly while having pacy counter-attacking options in the form of Mané, Salah and Ox. (The speed of all three was showcased in the run-up to the first Liverpool goal, during which all three left the West Ham covering defence behind and advanced menacingly on the poor lone defender still between them and the goalkeeper.)
And so it turned out to be. While there was a gap in quality between the teams, for most of the game the Hammers were battling us hard in midfield, setting up passing moves and trying to make runs and commit players forward. That was completely unlike the games where we’ve faced ultra-defensive setups like United, Huddersfield, Burnley and Newcastle, which more or less ceded all the initiative to us. West Ham put some decent moves together and if they had enjoyed the luck that some of the aforementioned teams had (such as scoring an early through ball to Ayew in the 8th minute) they might have gotten a couple more goals.
The tactical tweak by Klopp engendered some interesting possibilities. The clearest of these was Salah mostly running through the center between lines or trying to catch the last defender out, both of which he did well with his pace and movement, thereby opening up other channels for this team mates. In place of Salah in his usual spot, Ox ran the channels superbly. This seems to be a good setup against teams that are more likely to get over the halfway line, with Liverpool better able to absorb midfield pressure and springing forward very quickly through the channels, especially with Salah drawing attention in the center.
But perhaps the most pleasant surprise of the game was the sudden turnaround in Liverpool's injury list. Heading into this game, the team seemed crisis-hit: Wijnaldum looked to have twisted his ankle against Maribor, Mané and Lallana were still on the road to recovery, Coutinho's injury looked more serious than expected. Then Henderson appeared to have been ruled out on the day of the game itself.
All of a sudden both Mané and Wijnaldum were ready to start, the former, in particular, providing a huge boost to Liverpool and a telling contribution in the form of two assists. With Lallana and Coutinho due back at the end of the international (fingers crossed no Liverpool player gets injured during the break!), and hopefully Clyne edging closer, Klopp could have a very strong squad to see out the end of the year and the traditionally crowded Christmas to New Year's window.
