Jyoti Basu was a lousy administrator who is largely responsible for the decline of Bengal. But that said, the guy was a great statesman, possibly the best in that class because of his political shrewdness and sharpness of mind which is incisive even at 95! Lot of us don't know that his writings and speeches are a treasure in Constitutional democracy..
In short, a BAD and FAILED administrator who had the potential of being India's best statesman/diplomat ever.
