What is the magical property of bricks? A question of MORE

Was not gradual decrease in run splits. 2001, 2002, 2003 running 1:30 splits…then 2004 I started doing bricks and ran a 1:20…2005 did more ran a 1:19…2006 did same as 2005, but sometimes would do 5X1 mile off the bike instead of just 45 min hammer, ran 1:18