Well, the whole article is about the flaws in the format :) But the answer in this case is Huffman coding. The most common sequences compress to just a few bi

Well, the whole article is about the flaws in the format :) But the answer in this case is Huffman coding. The most common sequences compress to just a few bits, but backreferences and such are not byte-aligned, they just follow literals in the bitstream. Aligning things to bytes would significantly reduce the compression ratio.