This could well be complete rubbish, but how about this for a sytem of working out what theoretically is your best twitch ever....? As I said, it may very well be complete rubbish.
The factors to consider are
1) The twitched birds rarity value.
2) Distance.
3) Ease of travel (including cost).
4) Quality of views.
5) Ambience (the friendliness of the crowd, weather, scenery, was it your birthday etc...)
I say you give each one a rating out of 5.
So for example this is Jane Turner's fantasy ultimate twitch:
1) Great Auk (5/5 - as rare as you can get.)
2) On the sea from her house window (5/5 - no distance.)
3) No travel nor cost, other than to the computer to tell all her BF chums the good news (5/5)
4) At high tide it was showing to within 5 metres never diving and providing frame filling photos (5/5)
5) Jane had just won the lottery the night before & it was a fantastic hot, summer day (5/5)
So the ultimate score is 25.
Or is the distance and travel difficulty part of what makes a twitch great?
Here is one of mine I've just thought up:
1) American Robin (4/5) - is 5 too low a number?
2) Manchester - Godrevy in Cornwall 370 miles (2/5 ie lower score for further distance)
3) Only cost petrol, overnight drive shared between 4 people and no traffic (3/5).
4) Excellent prolonged close views allowing for quality digi-images and bird showed after very short while (5/5)
5) Warm, dry and bright and very nice, friendly, large crowd with no hostility and good company as well dramatic scenery of St.Ives bay behind us (4/5 - 5 has to be something exceptional ie your wedding day etc...).
So that equals a Quality Twitch Index (QTI) of 18.
And you can't count failing to see a bird only successful twitches.
Have a go ... or if you have a life then do something else worthwhile!!!
Tom.
Here is another one, the American Coot on Shetland that I saw in January:
1) American Coot (5/5)
2) Roundtrip of over 1,400 miles (1/5)
3) 6 hour drive to Aberdeen, 12 hour ferry, 30 minute walk, but very cheap and surprisingly easy to do (3/5)
4) Excellent, prolonged views but in slightly dull light (4/5)
5) Great fun getting drunk on the boat, excellent fry up after seeing it, fantastic selection of birds, very helpful local birders, girlfriends birthday & good weather considering the time of year & location. (5/5)
QTI - 18.
And another. This is quite addictive.
Ferruginous Duck at Chorlton Water Park in Manchester.
1) Ferruginous Duck (3)
2) Under 2 miles away (5)
3) Quick drive and no cost (5)
4) Showed very well in good light but a bit distant and occasionally skulking in reeds (4)
5) Firecrest also at the same time, but not a particularly nice place (3)
QTI - 20.
It doesn't quite work, because there is no way I preferred that to the other 2.