I am not totally convinced by the pressure index. There are a hell lot of factors to be taken into account. Last World Cup, India had much more pressure playing Kenya in the semi-final than the previous game in the same cup. The reason was the rain. Within 25 overs, if the game is disrupted due to rain, it would've been called off. However, after 25 overs they would have decided India as the winner by D/L method. But the pressure was was very, very much on India, and Ganguly, in order to speed things up, introduced Sehwag and Yuvraj (spinners) to speed up the over rate. The pitch was not welcoming and the bowlers DESPITE THE RUN RATE VERY MUCH UNDER CONTROL, were under a hell lotta pressure.
It was a unique situation, sure, but similar "types " of pressure situations occur once in every 5 ODIs for the Test playing nations (against one another).
