Playbook: Upwind 2.1

As Red approaches Blue, the discussion is whether or not Yellow can affect Red if she tacks, and how important it is to get left.  If Red is slightly bow out, she might be safe to tack and force Yellow to tack, but if the two boats are bow even (as pictured), Yellow will have the opportunity to tuck in tight to leeward of Red, and prevent Red from sailing her groove.  In this case, Red might need to take two more tacks, which would put her behind Blue, and introduce several opportunities for mistakes.  As such, assuming Red wants to go left, the playbook solution to the scenario is as follows:

Red should duck Blue and use Blue as a blocker to go to the left, that way there is no way for Yellow to lee-bow Red (which she would/should probably do if Red tacks before Blue). In this situation Yellow will likely lee-bow Blue and force them to tack out, or at least make it very hard for her to sail full speed.

If there is a line of boats above Blue that Red would have to deal with if she ducked Blue, Red should go early and make Yellow make a decision to tack or duck. If Yellow lee-bows, then Red might have a chance to double tack.

Comment below if you have another solution!