The sweet spot
Our resident racing expert Mark Rushall considers whether what might look like the perfect place to start is truly the best option, or could greater advantage be found elsewhere?
Picture the scenario: our rival in the RS200s has made the textbook start - the most windward boat at the starboard biased end, sailing at full speed, ahead of all the faster boats. We’ve started on a transit in the middle of the line: first gain to them. Have we lost the race already?
Five minutes later, we’re able to tack and comfortably cross ahead. Where did they lose out? Certainly not on speed; we’ve raced each other enough to know that the dierences are minimal.
While line bias is always significant, there are some other questions worth considering before fully committing to that seemingly ‘perfect’ spot on the line.
Here are some questions that will help you to pick the sweet spot...
Why is the line biased?
A biased line on an upwind start is not square to the wind. If nothing changes, starting at the end closest to the wind gives an instant advantage. When Red tacks (fig 1) he’ll cross behind Green. You can think of the beat as climbing rungs of a ladder: the green boat has essentially started on a higher rung! Fine if nothing changes, but what if it’s a shifting breeze, and the reason for the starboard bias is that at start time the wind’s at the right hand extreme of the range? As it shifts steadily back toward the left (fig 2) the ladder rungs twist correspondingly. If the wind is in a left phase when the red boat converges on port tack, positions are reversed and Green’s apparent advantage is gone. Could Green have done anything to protect his position? Yes, he could have sailed low and free in fast forward mode to close down the
‘leverage’ between him and Red, but that is pretty dicult in displacement mode or when there are other boats on the start line that you need to take into account.
Can I ‘bank’ the gain?
In fig 3, the wind has shifted left at start time, giving a port biased line. Red makes a great pin end start but can’t tack and clear the boats to windward. As the wind shifts right, the boats to windward are lifted around Red, who loses her initial advantage and more. If Red was clear to tack immediately onto port tack, she could cross ahead of the other boats before the right shift, and secure her bias gain.
Where is the course axis?
Look where the windward mark is in fig 4. Red’s position is now even more vulnerable in a shifting wind. On a square beat, when the wind swings left and Red tacks, Green can also tack onto port, maintaining the status quo. Tacking back onto starboard in the next right shift will put Green back in the driving seat. But with the skewed beat, any time on port tack will take Red straight out to the layline: once there, a shift in either direction is a loss.
Where are the gains?
In our club race, there was another strategic priority. We were beating against the tide, with shallow water to the left. Starting further down the line got us into the slacker tide on the left more quickly: though if there had been more starboard bias we may have been vulnerable to faster boats sailing through to windward while the feet was compressed. Starting in a position that gets us to the gains sooner may be more significant than the early line bias gain. If the gains are to the right, and the line port biased, starting to the left of the bulk of the fleet may give a better chance of a quick escape route.
Where are the obstacles?
Mixed fleet racing in both keelboats and dinghies is partly an obstacle course race. The ideal starting position for a given situation in a one design fleet could be sub-optimal in a mixed fleet if there are slightly faster, higher pointing boats just to leeward, or a procession of bigger boats lining up to power over the top with no prospect of tacking to clear your air.
'Starting in a position that gets us to the gains sooner may be more significant than the early line bias gain'
THE REACHING START
Apply the same principles to weigh up the options on a reaching start...
Which is the biased end?
This time, the biased end is the one that gives the shortest route to the next mark. Again, there may be good reasons for avoiding it. If it’s a really short leg it might simply be better to defend the side that will give the inside line at the first mark.
What is the fastest route?
Single-sail boats sail faster on a close reach than a broad one. The fastest route may not be the shortest. Even if the windward end is closer, it may be faster to beam reach from the leeward end. Or it may be that the windward end enables a spinnaker to be flown, while the leeward end does not.
Where are the gains?
If one side of the course has more pressure, or more/less tide, the leg may be decided by who gets to the gain side first. In that case pick the start position relative to the gain, rather than the first mark.