Michael Cole referenced the Brock Lesnar and Undertaker match at this year's Hell in a Cell as the "final chapter in a 13 year rivalry" - so in that case, why is chapter one of this particular book their WrestleMania XXX match? Wouldn't that make it an 18 month rivalry? Surely since it's a 13-year rivalry the first chapter should be their match at Unforgiven 2002? No?