Really the biggest difference this year as opposed to the last few has been health. The few key injuries the Yanks did suffer were to the bullpen, where they have the most depth. Taillon/Sevy/Monty are all pitching well and that's not unusual given their history, they've just spent too much time on the IL in past seasons. Same with Judge/Stanton. Others have really elevated their game this season such as Trevino/Cortes/King, and you also have Gleyber/DJ having bounce back seasons. Plus the defense has been astronomically better across the board. All of that has added up to a historically great start, and hopefully the injury luck continues.