Monday, November 5, 2012

Play 17 and the Shake and Bake

This post stems from a conversation I had with a coach at a team-race event.  The coach was complaining about a bunch of calls his team never seemed to get in their favor.  Naturally, he wondered how we umpires could screw up so badly.  From my experience and his description of what the sailors were doing, I don’t think we screwed up, at least not most of the time.  I told him I think the play, which I'll call Play 17, is a high-risk, low-profit move. 

The play is designed for Blue to break a trap at Mark 3, and goes as follows: Yellow sets a trap by waiting on starboard tack near the mark.  Blue approaches the mark on starboard tack and A forces her to go right, looking downwind.  (Recall that rule 18.4, which would normally prohibit Yellow from sailing farther from the mark than her proper course before jibing, is deleted in team racing.)  Yellow wants to drive Blue far enough away, and for long enough, to allow a teammate through or at least to slow the race.  Blue, on the other hand, wants to force Yellow to return to the mark and round it.  So Blue luffs up sharply (maybe even head to wind) at position 3, to break the overlap and put Yellow clear astern.  When she bears off again the overlap is re-established, but now rule 17 applies.  This means Yellow must bear away onto her proper course, which takes her back to the mark. 

The animation above shows Play 17 working about as well as Blue could hope for.  Once the overlap is reestablished at position 4, Yellow is forced to bear off onto a run.  She then must jibe back to the mark to avoid sailing out of the zone and having Blue establish mark-room on her, and  Blue follows her.  Note that Blue carefully avoids overlapping to windward of Yellow because then Yellow would have the right to luff Blue again, and without mark-room Blue cannot go between Yellow and the mark.

On the face of it, this seems like a good play.  A variation is even shown in Team Race Call  J6So, why, in the dozens of times I’ve seen this play, has it worked maybe twice? 

Well, for a bunch of reasons:
1.       About 60% of the time (my fellow umps, in an informal poll the other day, said 80%), Blue never actually breaks the overlap.  Thus when she bears off again, rule 17 still applies and she’s accomplished nothing except to waste time, which of course is her opponent’s objective.  

2.       Another 10% of the time, the umps don’t happen to be exactly lined up to see Blue break the overlap, and as a result don’t credit her with doing so.  (Look at how marginally Blue breaks the overlap in the scenario above, even though she luffs above close hauled to do it, and imagine how precisely the umpire boat would have to be, to see that the overlap is broken.)

3.       Even when Blue has broken the overlap she frequently hails Yellow to take her proper course before the overlap is reestablished, then protests her for not doing so.  Of course, at that moment there is no overlap so rule 17 doesn’t apply and Yellow doesn’t have to do anything.  So the umps green-flag it. This is particularly a problem for Blue because she may think the green and white flag is because the umps never saw her break the overlap.

4.       Even if all goes well, Blue doesn't gain much.  Yellow’s proper course limitation doesn’t begin until the overlap is re-established, and even then she only has to turn in a kind of lazy curve back toward the mark – an abrupt turn is slow, and therefore not her proper course.  By the time she finally jibes back to the mark, her objective has generally been accomplished.  

What we umpires see all the time is that when Yellow doesn’t bear off onto a proper course because she doesn't think the overlap was broken, Blue forces the issue by bearing off or, worse, jibing.  At that point she’s failing to keep clear (under rule 11 if she only bears off, and under rule 10 if she jibes onto port tack).  So she ends up with a penalty.  If she protests Yellow under rule 17 the two penalties are likely to result in the same relative positions as at the outset, only with a huge delay for the spins.  Again, this is what Yellow was trying to accomplish in the first place.

Worse, there's a good counterplay, first told to me by Charles Higgins, a sailing coach at Old Dominion University.  He calls it (for no reason known to me) the "Shake and Bake".

The Shake and Bake is really easy: Yellow simply doesn't let Blue reestablish the overlap without fouling.  When Blue luffs up, Yellow stays below her, clear astern and aimed just inches from the port side of Blue’s transom.  Now Blue can't bear off and reestablish the overlap without immediately breaking rule 11 (or, worse, jibing and breaking rule 10). Note that it doesn’t matter whether Yellow leaves the zone, because she has right of way when Blue reestablishes the overlap.  Also, rule 15 doesn’t apply because Blue establishes the overlap by bearing off.
Yellow’s obligation under rule 17 doesn’t begin until the overlap is re-established, which is approximately when the foul occurs.  Of course, Yellow avoids actual contact with Blue, bears off and protests.  If she wins the protest, she gains a huge advantage.  If not, she has still wasted a fair amount of time and therefore accomplished her purpose.

So if Play 17 isn't much good, what should Blue have done when Yellow set the trap?  Depending on the circumstances, she has three options that are better than Play 17.

First, she could have avoided the original overlap by jibing at position 2, going astern of Yellow and jibing back.  This is effective if the next blue boat is on the left looking downwind, or if Yellow has a teammate coming in on the right.  Sitting behind Blue, Yellow is in a position to prevent any member of the other team rounding the mark astern of Yellow, and if Yellow sails too far from the mark, Blue can quickly jibe around the mark and be ahead of her.

Second, if Yellow is trying to help a yellow teammate get ahead of Blue, Blue could turn back against that opponent and hold her back, using the same play Yellow is using on her (i.e., she should apply the Golden Rule of team racing -- do unto your opponents as they are trying to do unto you).

Third, there’s a better play that works especially well if the boats are keelboats:  at position 3, Blue tacks and turns hard toward the mark.  Yellow is at that point outside Blue's line and cannot force her starboard-tack advantage without breaking rule 16.1.  If Yellow tries to jibe out, she almost always has to leave the zone, so now Blue has mark-room.  If Yellow tacks, she loses mark-room and is now astern of Blue.

The reason this tacking play works particularly well in keelboats is that when Blue luffs up she develops good rotational moment into the tack.  By the time Yellow bears off to jibe around, Blue has the advantage.  But the tacking play works even for dinghies -- Charles says he has conducted tests that show the tacking play to be an effective play for Blue even in 420’s and FJs, as long as Yellow heads up to approximately a beam reach, or above. 

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