Google announced yesterday a new compression algorithm they call "Brotli." They bill it as

... a combination of a modern variant of the LZ77 algorithm, Huffman coding and 2nd order context modeling...

I'm no compression expert but I do know that the Lempel-Ziv algirothm offers one of the best speed:compression ratios for practical use, and Google claims that Brotli operates approximately as fast as zlib while achieving compression ratios 25% better than their previous algorithm, Zopfli.

Point is, I sincerely hope this format takes off and that they choose .bro as the file extension. The tar-related jokes practically write themselves: "Do you even compress.bro?"