Alpha and beta separation. Reading 27 index, capable, position, japanese, long

amqata

On page 238 of the cfa book, using futures instead of long/short to port alpha, the books says that one has to short futures on the manager of the japanese index and take a long position on the s and p. this sounds a bit counter intuitive. Wouldnt we want to be long the japanese managers alpha since it says that the manager is a capable one? Or am i assuming too much with the word “capable”