How good is Colle System?

I played it on accident, but how good is it?

It's perfectly OK for White.

It's also perfectly OK for Black, though.

If you like passive openings, this is good. However, it lacks bite and you would probably enjoy the Queen's Gambit more. I don't play it as White but if you were interested, I found this great study on it here.

Colle is fine.

Colle-Zukertort is better.

Best thing since sliced bread....you'll win every game.

All sound openings are good, unless you don't understand why you play "this" or "that". In that case, even the soundest of openings are very bad.
Both Colle systems (Zukertort with an early b3, Koltanowski with an early c3) usually transpose to colors reversed QGD structures, with an extra tempo for white. Not a terribly agressive approach, but stilll perfectly sound, and giving a lot of options to outplay your opponent IF you understand the positions better than him.

Ding is trying to show us!

Afaik it is good if Black played an early e7-e6 and cannot develop his Bc8 to f5 or g4.

You are a prophet. Ding has just won the game because of his "passive" choice...

Me guesses you are overestimating your knowledge and understanding of the game. Some humility won't harm you.

IMO the concept of playing Black openings with reversed color + a move more can't be really bad for White (even 1. a3 e5 2. c4 can't be bad, it is just a a Sicilian with reversed color + a3) but can't really be good about the opening itself because I think White doesn't really try to exploit the advantage of one move more form the start to play "an opening with advantage".

So in short the question is rather about how good the player is playing the Colle system than the Colle system itself which I don't think is so much of a problem.

Yet another prophet. Ding won against Nepo a few minutes ago with the Colle- Koltanowski...

And so it doesn't matter that it's almost always playing the Colle-Zukertort system.

One could play Bongcloud and win if the opponent decides to play that suicidal f5 move.

Welp.....

To be fair it seems Ian blitzed out while having all the time in the world. This wasn't one of Dings supercomputer level accurate games. Yeah, that French game still hurts.

The Colle is just equal, not particularly good or bad. Compared to the Queen's Gambit, it's pretty passive and unambitious.

It's very playable and a good choice.

Colle-Zukertort would have my preference over Colle-Koltanowski, though both are fine ( maybe not the best day for this statement 😁 ).

Keep in mind we are talking about systems that Capablanca and Rubinstein had played, the masters of the QGD themselves. Yusupov, a super GM of the past, had played the Colle Zukertort as well.

It's true that White doesn't strive for an advantage, though I'm not sure what's the advantage White gets in a QGD, which I play with both colours.

It's about equal positions and if one who knows their quirks and little details better than the opponent, then an advantage may come.

I'd ignore the voices that say that it's not good and if you like it, then learn it.

Also, there are some good resources to get you started on this ( Palliser has a book d-pawn attacks, Karpov has a recent book on these systems ), as well as high level games to study.

Capablanca used to play the Colle especially while he was evolving, perhaps he used the time he saved for perfecting his endgame technique ?

At some point study in the future the QGD too, because it's got many nice concepts and stratagems but the Colle is a nice system to start out with and keep later on as well to alternate your play and have the opponents guessing what to prepare for.

I think that was the intention. With only a few games left in the match, Ding needed to make things messy and complicated. The eval bar was screaming that black had the full point in hand, but it wasn't easy to find.

Ding's play was a gamble, but it paid off.

yet another game where Ding played the opening to draw and didn't manage to achieve his goals😁

To be fair, the result had nothing to do with the opening. Ding managed to get an extremely complicated position on the board, where mistakes by both sides were inevitable. It was a risk that paid off, and the lesson learned is that chaotic positions may well occur from very quiet, "unambitious" openings.