Given how I've found it hard to find basic info in past versions of the BA site, it's actually pretty easy to find the chart in the current version, IMHO. Not much detail on rules, though.

exec club>redeeming BA miles>Redeeming with our partners
https://www.britishairways.com/trave...club/_gf/en_us

Redeem your BA Miles on more than one partner airline

Use the table below to calculate the number of BA Miles you will need to redeem for a flight where the itinerary includes:
Two or more oneworld(TM) partner airlines (not including British Airways) or
Three or more oneworld(TM) partner airlines, if the itinerary includes British Airways.
Click here for a list of oneworld(TM) and other partner airlines.
To calculate the number of BA Miles required, add up the number of miles for each sector of your journey and refer to the table below.
Distance Range (miles) Economy
0 – 1,500 30,000
1,501 – 4,000 35,000
4,001 – 9,000 60,000
9,001 – 10,000 70,000
10,001 – 14,000 90,000
14,001 – 20,000 100,000
20,001 – 25,000 120,000
25,001 – 35,000 140,000
35,001 – 50,000 160,000
Base mileage required for return travel in economy cabins.
For further information about multi-carrier redemptions, please contact your Executive Club Service Centre or your Dedicated Reservations line