IRC racing

[howard easton]

Interesting but what evidence is there that the TCC calculated by VPRS are any closer to real life performance than those calculated by the VPPs used for IRC and for NHC and , for that matter, Byron? If they are accurate then they are an attractive cost alternative for IRC except that they arent that portable. If they take into account issues like sailcloth, numbers of keels, props etc then they would be a good starting point for NHC adjustment programs to give a performance based handicap. That could be very useful.

Mind you, they wont get round the issue of a wide disparity between boats in a fleet. I cant think of a handicap system that would allow Kerenza in his Match 42 to race with ( say) a Sadler 29 bilge keel.

 

[flaming]

I cant think of a handicap system that would allow Kerenza in his Match 42 to race with ( say) a Sadler 29 bilge keel.

If you're trying to race boats as disparate as that then you have bigger problems than what set of numbers you use for the results...

 

[H4B]

Interesting but what evidence is there that the TCC calculated by VPRS are any closer to real life performance than those calculated by the VPPs used for IRC and for NHC and , for that matter, Byron? If they are accurate then they are an attractive cost alternative for IRC except that they arent that portable. If they take into account issues like sailcloth, numbers of keels, props etc then they would be a good starting point for NHC adjustment programs to give a performance based handicap. That could be very useful.

Mind you, they wont get round the issue of a wide disparity between boats in a fleet. I cant think of a handicap system that would allow Kerenza in his Match 42 to race with ( say) a Sadler 29 bilge keel.

Back to the point I made, some pages back, about classes within IRC . If they are racing within a club then NHC will over time find a winner. But chances are, in the real world, one of them is going to get pi**ed off!

 

[H4B]

Interesting but what evidence is there that the TCC calculated by VPRS are any closer to real life performance than those calculated by the VPPs used for IRC and for NHC and , for that matter, Byron? If they are accurate then they are an attractive cost alternative for IRC except that they arent that portable. If they take into account issues like sailcloth, numbers of keels, props etc then they would be a good starting point for NHC adjustment programs to give a performance based handicap.

Not quite sure what you're saying here . Isn't that where we are with NHC? , the base numbers only have to be ' in the right ball park' because they change after each race based on performance . It is the rate of change that was wrong in the first draft but that has , I understand, been tweaked.

 

[howard easton]

If you're trying to race boats as disparate as that then you have bigger problems than what set of numbers you use for the results...

Exactly, but thats the problem with many clubs once you leave out the keen IRC types. What remains, the NHC fleet if you like, is as disparate as that. We split it into 2 but even then we have TCCs from 0.9 to 1.016 in NHC1 and from .756 to .865 in NHC2. With tides maxing out at 3.6kn in the area we race in, you can see that the difference in relative performance between springs and neaps, windy and light are huge.

But we have no alternative but to make the best of it and the fleet sizes suggest people are enjoying themselves.

Not quite sure what you're saying here . Isn't that where we are with NHC? , the base numbers only have to be ' in the right ball park' because they change after each race based on performance . It is the rate of change that was wrong in the first draft but that has , I understand, been tweaked.

One problem with the current approach is the degree of adjustment is unncessarily large because the initial figures are so far out - it would be much better if the NHC numbers could be adjusted for things like twin keels, three blade fixed props, fancy sails etc before the start of a series. Furhermore there is something funny in the adjustment system that gradually moves successful boats upwards. For example, a well sailed Impala had migrated to 0.971 by the beginning of the last series from 0.897. Imagine what would have happened had another Impala joined the fleet at 0.897. The NHC lacks the primary yardstick boats that the old PY had.

There is a further issue and thats with regattas. Starting off with poor TCCs and relying on rapid alternation means that some boats are very much disadvantages in the start races and they cant catch that up in a couple of days

 

[H4B]

But we have no alternative but to make the best of it and the fleet sizes suggest people are enjoying themselves.

That's good to hear and surely the most important thing. As in all clubs well done to the few that make it work!

 

[H4B]

Exactly, but thats the problem with many clubs once you leave out the keen IRC types. What remains, the NHC fleet if you like, is as disparate as that. We split it into 2 but even then we have TCCs from 0.9 to 1.016 in NHC1 and from .756 to .865 in NHC2. With tides maxing out at 3.6kn in the area we race in, you can see that the difference in relative performance between springs and neaps, windy and light are huge.

But we have no alternative but to make the best of it and the fleet sizes suggest people are enjoying themselves.



One problem with the current approach is the degree of adjustment is unncessarily large because the initial figures are so far out - it would be much better if the NHC numbers could be adjusted for things like twin keels, three blade fixed props, fancy sails etc before the start of a series. Furhermore there is something funny in the adjustment system that gradually moves successful boats upwards. For example, a well sailed Impala had migrated to 0.971 by the beginning of the last series from 0.897. Imagine what would have happened had another Impala joined the fleet at 0.897. The NHC lacks the primary yardstick boats that the old PY had.

There is a further issue and thats with regattas. Starting off with poor TCCs and relying on rapid alternation means that some boats are very much disadvantages in the start races and they cant catch that up in a couple of days

You make a good argument for IRC, perhaps not your intention.

 

[howard easton]

You make a good argument for IRC, perhaps not your intention.

Not at all. If anything, its an argument against IRC where if the number is wrong in the first place it stays wrong for ever. And which in turn invites some people to buy success with fancy kit, and boats designed to beat the handicap. At least NHC adjusts to reality. My argument is that the NHC is right in principle for the casual racer in a cruising boat but the implementation has IMO been bodged. Both the original numbers and the program to adjust race to race.

The frustration is that the old PY system worked better. The start numbers were nearer reality, the adjustment race to race worked well. And most irritatingly of all, there is a simple formula which converts a PY number into a TCC, so the work to derive the NHC wasnt even necessary.

 

[H4B]

Not at all. If anything, its an argument against IRC where if the number is wrong in the first place it stays wrong for ever. And which in turn invites some people to buy success with fancy kit, and boats designed to beat the handicap. At least NHC adjusts to reality. My argument is that the NHC is right in principle for the casual racer in a cruising boat but the implementation has IMO been bodged. Both the original numbers and the program to adjust race to race.

The frustration is that the old PY system worked better. The start numbers were nearer reality, the adjustment race to race worked well. And most irritatingly of all, there is a simple formula which converts a PY number into a TCC, so the work to derive the NHC wasnt even necessary.

Did you really August PY numbers ' race to race' ?

We adjusted them at the end of each series.

IME club skippers are seldom universally happy with any handicapping/rating system used at club level. I would however agree that the base numbers for NHC are not logical and bare little resemblance to what a boat might expect for IRC. I hope for something around 0.880 , when I get round to the application whereas in NHC my base is 0.909 and we finished the season on 0.941. In a local regatta running their own system , similar to IRC 0 I am given 0.920 and struggle.

 

[howard easton]

Did you really August PY numbers ' race to race' ?

Yes we did. That was how PY was supposed to be used but I know that some clubs didnt do that. One that I am a member of didnt used to adjust them at all at one time and used them as a sort of faux IRC.

IME club skippers are seldom universally happy with any handicapping/rating system used at club level. I would however agree that the base numbers for NHC are not logical and bare little resemblance to what a boat might expect for IRC. I hope for something around 0.880 , when I get round to the application whereas in NHC my base is 0.909 and we finished the season on 0.941. In a local regatta running their own system , similar to IRC 0 I am given 0.920 and struggle.

Seldom?? Dont you mean never? At one club every single racer I spoke to reckonned that the new NHC numbers put their boat at a disadvantage compared to the rest of the fleet!

The difference between your starting 909 and finishing 941 shows you must have had some success ( well done!) and it also illustrates what I said about a general upward creep in TCCs . We have had exactly the same experience. Someone once gave me a link to the methodology of the adjustment software and on a very short read through it seemed to me that they had built this creep into the maths of the system. There wasnt the same issue with the PY software.

As for the base number, if its any consolation my conversion from PY to NHC mirrors yours almost exactly. I had a look at the numbers for two standard boats, the Impala and the Sigma 33 and the Sigma has gained something like 3.5% on the Impala in the changeover if I am reading my scribbled notes correctly.