Complex sentence: The Advance Variation has since been revitalized by aggressive lines such as the Bayonet Attack (4.Nc3 e6 5.g4) favored by Latvian Grandmaster Alexei Shirov or the less ambitious variation (4.Nf3 e6 5.Be2 c5 6.Be3) popularized by English Grandmaster Nigel Short.
Split into simpler sentences: The Advance Variation has since been revitalized by aggressive lines such as the Bayonet Attack (4.Nc3 e6 5.g4) favored by Latvian Grandmaster Alexei Shirov. The less ambitious variation (4.Nf3 e6 5.Be2 c5 6.Be3) was popularized by English Grandmaster Nigel Short.