John F. As the inventor of the term 'boundary play' I would quibble with its use here. A I have explained on L19 that the term derives from the Chinese 'shou' and is actually better rendered as 'boundary-settling play' - I use 'boundary play' as shorthand. The term as being used here is simply a move 'on' a potential boundary. There is no settling involved. It could become a settled boundary if White answers accordingly, but even then it would be debatable whether the boundaries (plural, as implied by shou) are all settled. Shou has as its basic meaning 'harvesting ' or 'garnering' and so, to use the term, properly, you need to be able to point to some territory that has been securely gathered in. If Black had a stone around K5, Black 1 might just be describable as shou, but the more usual term would be kakoi if White did not answer in that area and so settle the boundaries. In short, shou gives territory, not influence. And if Black is playing this way to get influence, he would not use 'kakoi' but 'big point' (or Tennozan or the like).