Chelsea are unbeaten in all competitions since Tuchel succeeded Frank Lampard in January and have conceded just two goals in his 14 matches in charge.
Allardyce takes his side to Stamford Bridge on Saturday, and he said of the German's start: "Fantastic because he's done the right thing. Start with clean sheets and then you build from there. He's done that absolutely magnificently.
"That's not to say that Chelsea are not very entertaining, because the quality of the players they've got at the other end, they are, and obviously I'm very jealous about that.
"But our players have equalled and matched teams like Manchester United here, Liverpool away and Manchester City, so we've got to go and do the same to Chelsea, and that is play a very good tactical game on nullifying their strengths.
"But there's one thing that's going to be very difficult for us and that's break down that very good defensive unit he's got. It has been a very good start for him."
It does not bode well for the Baggies that they are the second lowest scorers in the Premier League with only 20 goals from their 29 games.
Allardyce said: "When you're in our position and they're in their position, you know before you go into the game that your possession stats are going to be lower than Chelsea's. It's making out the players to be most effective in those possessions.
"I think normally it's us playing counter-attacking football, playing quick, sharp, forward passes to maybe exploit the spaces Chelsea will leave. If we spend too much time slowing it down, passing sideways and backwards, they will come and do a high press and take the ball off us."
West Brom have, though, produced some impressive performances against the top teams and have taken points off Manchester City, Liverpool and Manchester United.
Allardyce said: "I'll remind them about the performance at Man City I watched on telly. I'll remind them about the performance at Liverpool away.
"I'll certainly remind them about the two performances at The Hawthorns against Manchester United and Everton, which we certainly should have got at least four points out of, if not six.
"That obviously didn't happen because of our lack of finishing quality but they've done it before so, if they can replicate that, they'll get themselves a chance to get a result or maybe even beat Chelsea.
"We have to keep going and keep believing, and hopefully the lads that get the chances start being more clinical and start trying to win us games of football."