This is in the OP.
Each book contains/allows :
C/U/R/VR , C Starting/ U Guaranteed/ U Guaranteed turn 1 research/ R Guaranteed, other effects
Book 01 : 3/1/0/0, 0/0/0/0, Find/Trade common
Book 02 : 3/2/1/0, 1/0/0/0, Find/Trade Uncommon
Book 03 : 4/3/2/1, 2/0/0/0, Find/Trade Rare
Book 04 : 5/4/3/2, 3/0/0/0, Find/Trade Very Rare
Book 05 : 6/5/4/3, 4/1/0/0,
Book 06 : 7/6/5/4, 5/1/0/1,
Book 07 : 10/7/6/5, 5/2/0/1,
Book 08 : 10/10/7/6, 5/0/2/1,
Book 09 : 10/10/10/7, 5/0/2/0, +8% research, -5% casting cost
Book 10 : 10/10/10/10, 5/0/2/0, +16% research, -10% casting cost
Is this still accurate? with book2 kinda sucking and book 7 being really quite good? (2spells added to research versus 6? most are 4 each (there's also a 3 and a 5)).
Is this to balance how good it can be in combination to use the 2nd book just for 1 combo spell? (It used to be closer to 4 per book in the past, iirc?) I think I've asked this exact same question before, years ago, but the chart has changed since the last time I asked
sorry if this is a silly question I should be able to figure out on my own.