Ikken-tobi from a stretch
This shape makes a 100% connection, eye-shape at a, and it is flexible, because at all times Black can decide to abandon either the lone stone, or the connected pair of stones.
(Liberties/stones ratio = 3; occurrence frequency = 6)
However, ikken-tobi from a stretch can be considered inefficient. This inefficency is unclear until white plays at the point marked a.
While this is effective, nikken-tobi from a stretch gives better influence around a, and the same play is still effective.
Here are a few other possible responses to the peep at the ikken tobi from a stretch. This first is probably the best: black should pressure the white stone. However, this leaves bad aji for black at a, so black should ideally have more influence around b than white to play this move. Alternatively, if the sequence started by pushes white back upward and leaves black with sente, black can then play at one of the points marked c to secure the connection.
Here is another possibility. White will not even play the sequence - if she knows what is good for her, but this response is generally too easy on white if she plays tenuki instead of .
is standard. It provides the farthest-reaching influence of the mentioned possibilites, though it may also be too easy on white.