I am old enough to have seen Mackay in his prime and he is my favourite player of all time. The comparison with Jenas, however, is not really fair.
The game has changed a lot since the 60s. Dave Mackay (or Chopper Harris or Norman Hunter) would not get through a match in the modern game without a card. Tackles from behind and shoulder-barging keepers were still legal in the 60s. Sendings off for foul play was almost unheard off. Today's game is also a lot faster and whatever you think of Jenas, he is a wonderful athlete.
I have never rated Jenas (I was against buying him in the first place) but the comparison with the great Dave is not fair.
Not even in his early days at the Toon?