He is already one of only two managers to have got the better of Pep Guardiola in three successive matches - so how telling will it be if Thomas Tuchel can rack up four wins in a row when Chelsea host Manchester City on Saturday?
The Chelsea boss never beat Guardiola when they both worked in Germany but followed in Jurgen Klopp's footsteps soon after arriving at Stamford Bridge when he racked up a trio of wins in three different competitions in the space of six weeks at the end of last season.
Tuchel's last triumph, in the Champions League final, was by far the most significant of those successes, and came after some so-called over-thinking by his opposite number saw him tinker with the tactics that had just delivered his latest Premier League title.
So, what has Guardiola got up his sleeve this time? And, with Chelsea top of the table and already looking in formidable form, how important is it for him and Manchester City that he gets this one right?
"It's all everyone at City is talking about," says their former midfielder Michael Brown, who will be at Stamford Bridge for Radio 5 live.
"I was working at their Carabao Cup win over Wycombe at Etihad Stadium on Wednesday and, whether it was fans, other ex-players or people in general, they were all saying 'what will Pep do at the weekend and will it be something different again?'
"It shows where he and the club are at. Everyone is judged by Pep losing games - whoever gets a result against him is big news.
"He's the one manager in the world where, if he is beaten, everyone looks into every little thing that could explain why it has happened."
'The best two tactical operators in the game'
Tuchel is not yet the same-sized scalp as the Spaniard, but his approach on Saturday will also be under some scrutiny. After all, he has done little wrong since arriving in England in January and, after conquering Europe, his team are currently top of the domestic table.
Like Guardiola, his adaptability is key to his continuing success.
"The most interesting thing for me about Tuchel this season is that I think he is dumping the 3-4-3 system that got Chelsea to the Champions League final and won him that game," says former Chelsea winger and BBC pundit Pat Nevin.
"They have started to look more like a 3-5-2 shape, with either Kai Havertz or Timo Werner getting much closer to Romelu Lukaku. Boy does it work well when you have got N'Golo Kante, Jorginho and Mateo Kovacic behind them in midfield.
"Of course Tuchel can still go back to his old formation when he wants to, even during a match. I am fortunate enough to be there on Saturday and I will be watching the technical changes in the game as closely as I will be watching the skills on the pitch.
"Tuchel and Guardiola are basically the best two tactical operators in the game right now when it comes to reading a game, reacting to what is happening and affecting it.
"At the moment, Tuchel's decision-making is great and seems to make a difference really quickly. Against Spurs last week, bringing N'Golo Kante on at half-time completely changed the game.
"But he is up against Pep again now and that is a game of chess above all others. He won the last one but, to be fair, Guardiola knocked his own queen over at the start with his team selection that day.
"So, Tuchel has not exactly got his number but I don't think he is fearful of Pep, whereas I think a lot of other people are afraid of his huge football intelligence."
Tuchel still trails 4-3 in head-to-head meetings with Guardiola but his recent run is only one of the reasons the fear factor in these games may have diminished - he has some inside knowledge too.
"There is an amazing story of Pep meeting Tuchel in Munich in 2014 when he was a young up-and-coming manager and had just left Mainz," Brown explained.
"Tuchel says what they talked about over dinner was how to play a false nine, especially in the biggest games.
"Tuchel took all of that information in, he was like a sponge. So, has Pep told him how he does it? If so, how does he then change it around if Tuchel is aware of the plan, or does he just need to do it better?"
What will Guardiola do next?
A false nine is among Guardiola's options on Saturday but he did something different each time he took on Tuchel last season, without finding a winning formula.
While he rested players in the FA Cup semi-final and changed his formation from 4-3-3 to 3-5-2 when they met in the league, his most infamous tweak came in Porto, on the biggest stage of all.
Trying to find a way to break down a Chelsea team that, like now, gives very little away, Guardiola decided not to use a holding midfielder in the Champions League final.
It was a bold plan, and it backfired. As Nevin says, Chelsea were soon at checkmate in that particular game of chess - but what will be Guardiola's next move now they are back at the board?
"Pep was brave in Portugal and wanted to dominate possession and get his midfielders on the ball high up the pitch," Brown says.
"That's why he emptied out that holding role, because he thought Ilkay Gundogan could get higher too, but it didn't work out - the counter-attack from Chelsea was just too good.
"Being away from home on Saturday, though, he will surely be considering a holding midfielder, whether that is Fernandinho or Rodri.
"Further up the pitch, he could use Ferran Torres as a more traditional centre-forward playing on the shoulder of Chelsea's centre-backs.
"In terms of his shape, he might have been tempted to go with three centre-backs again, because I thought they were the better team when they played that way against Tuchel's Chelsea in the league, but availability will govern Pep's selection and formation this time.
"You look at the centre-back area and John Stones and Aymeric Laporte have both been injured. Playing either of them might be a risk, so sticking with a back four is probably sensible.
"He also knows City have three huge games this week - they are at Paris St-Germain on Tuesday and then go to Liverpool next Sunday.
"That could affect his selection too, but I think his approach will be to focus on this game. He knows it will be tough, but he won't fear Chelsea - City will go all out to beat them on Saturday, and then adapt from there."
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