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. 

Thursday, November 1, 2012

Changes to the RRS for 2013-2016

The Racing Rules of Sailing for 2013-2016 have been published.  They go into effect on the first of  January 2013.  As usual, the rulebook has "change bar" marginal lines opposite any rules that have been changed in any way (except formatting).  To find the ISAF Submission that led to any particular change, consult the "Study Version of the Racing Rules for 2013-2016" posted by ISAF on their site.  

But if you just want an overview of what's changed and a short explanation of the changes, I'm providing below what I think is a complete list of all changes that aren't simple grammatical or formatting (potential game changes in bold):

Changes to the RRS for 2013-2016 

Definitions have been moved to the front of the book.

Def. Finish – “from course side” v. “from direction of the last mark”.

Def. Keep Clear – “making contact” (not necessarily with the other boat in the rule).

Def. Mark – object must be “accidentally” attached in order to not be part of the mark.

Def. Mark-Room – Removes “to” vs. “at” distinction of 2009-2012 RRS.  Only gives room to sail to the mark if the boat’s proper course is to sail close to it; grants “room to round the mark as necessary to sail the course”, which can be much less than proper course. But see also new rule 18.3(c)(2). 

Def. Party – for redress, adds the person or organization alleged to have made an improper act or omission.  See change to rule 62.1.

Def. Room – “including space to comply with her obligations under the rules of Part 2 and rule 31”.

Part 2 Preamble – “right of way” slight wording change.

14(b) “exonerated” instead of “shall not be penalized”.

Preamble to Section C of Part 2 – “When rule 20 applies, rules 18 and 19 do not” deleted.

18.2(c)(2) Tied into new mark-room definition.

18.2(e) “or by tacking to windward of the other boat”

18.3 passes head to wind and is then on same tack …

20        Order of rule: Hailing, Responding, Passing On a Hail to an Additional Boat

Makes it clear that a boat must respond to an improper hail; allows passing the hail on to another boat even if the initial conditions for hailing do not apply to the middle boat.

21 EXONERATION  Moves exoneration from rule 18 to cover all of Section C  -- big deal for rule 19.

Old rules 21, 22 renumbered as 22, 23.

22.3 (previously 21.3) “moving astern through the water”.

25.3 RC may use shapes for flags, as long as they look right.

28 Made two separate rules – sailing the course and string rule.  No real change.

41(a) “help for a crew member … in danger”.

41(e) delete recovery of crew member overboard – covered by (a).

41 “However, a boat that gains a significant advantage in the race from help received under rule 41(a) may be protested and penalized; any penalty may be less than disqualification.”

42.3(e) (new rule) “If a batten is inverted, the boat’s crew may pump the sail until the batten is no longer inverted. This action is not permitted if it clearly propels the boat.”

42.3(h) “after colliding with a vessel …” (used to be “boat”).

44.1 makes the scoring penalty an “alternative” (so by default either one or the other applies, not both).

44.1(b) makes clear that the penalty is included in deciding whether she gains an advantage.

49.2 Crew may sit with heads outside lifelines regardless of the material of the lifelines.  Lifelines must comply with the ISAF OSR.

50.4 Headsails can have big roaches – 75% midgirth – and still not be spinnakers.

55 “A competitor shall not intentionally put trash in the water.” (Applies at all times on the water.) Moves a common SI into the RRS.

60.1 “A boat may … protest another boat, but not for an alleged breach of a rule of Part 2 or rule 31 unless she was involved in or saw the incident;”

61.1(a)(3) Clarifies that a boat may protest under rule 28 any time until just after the other boat finishes.

62.1 extends redress for improper actions or omissions by OA, measurer, etc.

63.6 “testimony of parties present …”

63.6 “A member of the protest committee who saw the incident shall, while the parties are present, state that fact and may give evidence.”

64.1 “When the protest committee decides that a boat … has broken a rule and is not exonerated, it shall disqualify her …” Also, some reorganization – in particular, exoneration for being compelled to break a rule is now rule 64.1(a), not 64.1(c).

67 Delete the rule – deals with rule 42 enforcement when App P is in effect. Duplicates provisions in App P.

69 Broken into 4 rules: 1. prohibiting misconduct; 2. laying out the procedure; 3. MNA actions; 4. ISAF actions.  Only substantive changes: 69.1(c) specifies a standard of proof as “comfortable satisfaction” of the protest committee.  This is stronger than “preponderance of the evidence” but weaker than “beyond a reasonable doubt”.  It would seem to require unanimity, or at least no minority position after deliberation.  Note that while rule 69.1 applies only to “competitors”, rule 69.3 allows MNAs to take action against “against the competitor or boat, or other person involved, …”

70.1 New part (b) allowing appeals base on no hearing.

71.2 Allows MNAs to appoint new protest committees when upholding appeals.

76.1 Basically adopts the US procedure for excluding competitors, but not the US standard against race, religion, etc. 

78.2 No valid measurement certificate – simply cleans up wording.

81 Change in event dates – cleans up wording.

86.1 Can no longer change the zone size in SIs.

89.1 Obscure changes about who can serve as OAs. Defines “affiliated”.