Hanging Pawns: Good or Bad?

My First Experience

Initially, like any chess player I did not pay much attention to any specific sort of pawn structures. The hanging pawns was a concept that I had briefly heard mentioned and I found them quite pleasant to play with because my pieces somehow always managed to find activity.

This shallow mindset was challenged however when I came across a game by David Howell, while studying the Alapin Sicilian (incidently I recommend anyone interested in this opening to check out Davids's and Sergei Zhigalko's games with the Alapin some of them are absolute works of art).

Previously in the following position most players, including Howell himself, had opted for 9.Qe2.

And after 9...O-O 10.Nc3 Nxc3 11.bxc3 White can get the pawn structure with the hanging pawns on c3 and d4 once we take on d6. Or White can also play the position with a pawn on c3 and e5 if Black takes on e5 like in the game Howell, David (2340) - Littlewood, Paul (2380), BCF-chT 0405 (4NCL) West Bromwich 2004.

Then four years later, now a GM, Howell plays the following game:

He completely switches up his opening philosophy!
No longer does he go for hanging pawns or the dynamic c3, e5 pawn setup, but rather builds up much slower with a3, Qd3, Bd2, Nc3.

Is it really worth investing this many tempi, when you are able to reach a comfortable hanging pawn setup instead? Also it wasn't like his results have been bad with the previous system either.

This puzzled me. What has changed? Had his positional understanding increased or was this just a matter of taste?

Philosophy Of The Hanging Pawns

The big idea behind the hanging pawns is similar to the isolani - the player with the hanging pawns gets dynamic play and should try to keep the pieces and push the pawns forward at the right time while also angling for a kingside attack if the time is right.

Black's big plan on the other hand is to attack the pawns so that they prematurely advance and can be successfully blocked. If this can be achieved it will be almost impossible for the other side to generate any type of counterplay.

Game 1: Aronian, Levon vs Stevic,Hrvoje (2011)

The first game which I wish to share is this one by Aronian. I found it incredibly fascinating how easily he manages to place all his pieces on their optimum squares and then casually breaks through the centre with the d-pawn.

Game 2: Macieja, Bartlomiej vs Hernandez, Holden (2012)

The second game illustrates the biggest drawback behind the hanging pawns. Once they are blockaded the position becomes positionally lost, with very little chance to generate any type of counterplay.

Summary

Next time you encounter the hanging pawns ask yourself "Can they be blockaded?" and "What do my dynamic chances look like?".

I still don't know why David Howell played a3, Bd2, Qd3, Nc3 but what I do know is that hanging pawns are much more complex than I once thought. Specifically if they do not work out and are blockaded you have very little chance to turn the game around.

Here's a quick exercise to test your knowledge.

White to play: Are Black's hanging pawns weak or strong?