Someone explain the new setup system please

[PB111 12]

Ok, previously you could just add the numbers on the cards and they would add up to your PI 
Now i take out a card worth 150 and add a card worth 190 and my PI reduces by 1 

What gives?

[G1bby 24]

If you have a legendary card in your set-up, for example lightweight booster, it will add 30% lightweight to your set-up. If you then take out a card worth 150pts which is say 120pts lightweight and 30pts power it's real worth is 120+30% = 156pts + 30pts power = 186pts.

So if you're new 190pt card doesn't contain any lightweight then your PI won't change much.  

[PB111 12]

That sounds quite logical, I just can’t remember it being like that before the update.