Many heavyweight titleholders seek out an easy first defense. Newly minted IBF heavyweight champion Charles Martin seems to have a different strategy in mind. Martin took to Twitter to call out undefeated British heavyweight Anthony Joshua, who is almost universally regarded as the top prospect in the heavyweight division. Martin tweeted, “So my team tells me @anthonyfjoshua scared to fight me April 9. How much more time you need sweetheart? @EddieHearn.”  Joshua (15-0 with 15 KOs and a 2102 Olympic gold medalist) is promoted by Eddie Hearn.  Martin (23-0-1 with 21 KOs) is promoted by Warriors Boxing. Martin won the vacant IBF title on January 16th when  Vyacheslav GLazkov injured his knee in the third round