BE calculation by Riot is extremely misleading, 14% less than stated, math inside
First of all, their math assumes that you play a minimum of 2 games a day. In those 2 games a day it assumed you lose 1 and win 1, giving you your first win of the day. This is accurate because every game has 5 losers and 5 winners. However, the problem is that their math assumes you **always ** win one of your first 2 games played. This is just unlikely over longer periods of time.
With some pretty simple math we can conclude that 25% of the time, you lose both of your 2 games played and 25% of the time you win both games, but only rewarded with the FWotD once.
Math: 0.5 * 0.5 = 0.25 = 25%.
so 25% of the days you play, you're not going to get your first win of the day bonus. To calculate how much XP you lose, we use a 4 day model with 8 games and 50% win ratio, since that means that on one day out of the 4 you don't get the first win bonus (on average).
Games with 50% win ratio gives you 1824 XP. With 4 first win bonuses you get a total of 4124 XP. However, realistically, you only get 3 first win bonuses, which means you get 575 XP less, which is 14% less XP than what is represented in the original scenario.
This is made even worse by the fact that FWotD doesn't reset at the same time everyday, limiting the window for the so called "casuals" who play 2 games a day on average. I'm not going to factor this into the math because there are just too many variables.
By the looks of it, math isn't Riots strong suit, or they are intentionally misleading us, or it's an overlooked mistake. In any case, you're realistically not getting the same amount of BE/IP as you were before.