(Pawns) Two Against One In The Center:
Part of the Advanced Beginner's Chess Guide (Section 1) and the
Chess Strategies Guide (Section 2: Studying the Pawns)

(Pawns) Two AgainstOne In The CenterPoint Count Chess: [+]

This article includes my notes, additional images and interactive chess positions from my study of Horowitz & Mott-Smith's book, Point Count Chess.

Source:
Point Count Chess,
Chapter 1. Two Against One (p27-28)

Specific to Pawns ... this situation, where one army is down to one Center Pawn versus two adverse Center Pawns, is very common in openings. Diagram 1, below, shows Black with the advantage of two Pawns in the Center against one White Pawn:

Diagram 1: Black's Two Against One
Whenever someone mentions a Two Against One Advantage, or 2 v. 1, in reference to a Pawn advantage, it should be noted that we are talking about the pawns on the d- and e-files, to the exclusion of all other files (since there are so many definitions of Center, a new person could become confused and assign a point for situations of 2 v. 1 on the c- and d-files, for example, and that's not what we're assessing).

The following sequence shows how that very same Two Against One situation can arise from the Sicilian Defense:
Incidentally, notice after White's 4th move, that White is in possession of an advantage (a plus point) for Pawn on the 4th v. Pawn on the 3rd, though we won't go into that here.

Another example of Two Against One can be seen in Diagram 2, below, which occurs immediately following the King's Gambit Accepted:

Diagram 2: White's Two Against One
You can see how it happens, in the sequence below:
The advantage, of 2 v. 1, lies in the long-term potential middlegame advantage of:
• Better control of the four Center squares (d5, e5, d4, e4) with 2 pawns rather than only one;

• More possibilities of an Outpost in the Center with 2 pawns;

• And a potential endgame advantage that could possibly result in a Passed Pawn in the Center late in the game.
This is often counterbalanced by the more short term immediate advantage of 4 v. 3, where one pawn occupies a central square, and holds back the oppositions pawns from advancing, often leading to greater space, as well as a half open file in the Center that could be controlled by a Major Piece.

If one side has the advantage of 2 v. 1 and the other has 4 v. 3, points are awarded for both sides (see PCC, p.28). Subsequent play will transform one of these advantages into something lasting.

Also, be aware of the difference of Potential v. Immediate value / advantage, which H&M-S mention in PCC, between the final three paragraphs on page 27, continuing on page 28 of Point Count Chess.