Why are Rooks Better than Bishops?

Most of the basic chess instruction books tell us that knights and bishops are worth about three "points" or pawns, while rooks are valued at about five "points" or pawns. Of course, this is relative, and in any given board position this valuation may vary considerably.

But in general, it holds true. We can easily understand the rook's greater value than the knight, which moves slowly across the board. But what about the bishop? Like the rook, it can quickly scoot from one end of the board to another. Why should it be worth so much less than the rook? Have you ever pondered this or just taken for granted what the books tell us?

Look at the board below with only rooks. No matter where a rook is positioned, it can potentially attack 14 squares. This is true whether it sits in the middle of the board or right at the edge.


Now take a look at the "bishops only" board below. At best, a bishop can hit 13 squares, if it sits on one of the four center squares. At the edge of the board, it can only attack 7 squares!


There are two other reasons why rooks are generally superior to bishops. First, a bishop is limited to only one color square, so it is forever off-limits to half the board. And second, while bishops side-by-side can be strong, they are not as devastating as doubled rooks can be.

Now you know!