Is Mr. Jack Pocket balanced?
Short answer: No, 55% winning chance for the Inspector.

Here is a quote from the designer Bruno Cathala on balance in the game.

It is taken from a reply on Boardgamegeek


  concerning balance of the game, i just want to give you some statistics.
  The final balance has been made with testors belonging to the top of the mr jack players on internet (http://mrjack.hurricangames.com)
  
  And, moreover, an artificial intelligence has been developped to help us.
  
  I will speak here only about games played exactly with the final set rules.
  
  If i consider games played by human player against an other human player:
  
  196 games have been played
  108(55%) won by inspector (96 by primal goal, and 12 after hunting jack because he got 6 hourglasses at the same time he was identified)
  88 (45%) won by jack (53 by primal goal, 33 staying invisible after being hunted, and 2 by "dawn")
  
  now let's see what happens when the computer plays against himself:
  340 games have been played
  187(55%) won by inspector (140 by primal goal, and 47 after hunting jack because he got 6 hourglasses at the same time he was identified)
  153 (45%) won by jack (97 by primal goal, 55 staying invisible after being hunted, and 1 by "dawn")
  
  So.. that's the reason why i know that the balance is slightly in favor of inspector, but not enough to really create a problem. (Experience and/or tactic competence is much more important to win ;-))
  
  Hoping these results will interest you..
  all the best
  bruno