I have only 3 words to add to this discussion at the moment:
consistency,
consistency,
consistency!
Well maybe a few more. IMO, the way to pick pacelines is the way you have discovered - either through reading and testing the advice of others, or through your own trial and error - that you
consistently and
persistently make money doing do. For one person to advise another that such and such a method is wrong is to likely invoke a shrug from someone who knows full well that they profit from paceline selection using the 'disfavoured' method.
Maybe Sartin, or Bradshaw or Brohamer or Pizzolla each used and taught their respective dissimilar (or similar) approaches, but they are not here with you, by your side, as you select your lines today. You must do it by yourself, and you must do it the same way for each and every next race, otherwise you have no method at all (i.e. you approach is not 'methodical'). Since racing is chaotic and often unpredictable in the short term, while it can be predictable in the long-term, if you don't pick your lines using consistent rules you won't know if a WIN in a given race is the result of your method or merely random, OR whether a LOSS in a race is the evidence of short-term randomness or the result of a weakness in your method. Hence
consistency - in the long-run, you'll find out if you're headed in the right direction with your method.
I have seen perhaps more peoples' paceline selection strategies up close (at least using RDSS) than many here, and I can say with no care to whether folks believe me that there are some VERY different approaches to line selection AND some successful (profitable) RDSS users among them. In almost EVERY case I can think of, the people tend to pick their line or lines for horses
the same way race after race (allowing that lines for Turf routes may be chosen differently than lines for dirt sprints, and Graded races differently than for Maidens).
Consistency.
There is
Best of last 3 (SR, TE, CPR, Perceptor) comparable, roughly per Bill's example; there is
last line except when it's not comparable (but favouring
last); there is
not the best/not the worst rating of the past 'n' days (90/120/270 whatever) but sticking to the last 3 lines and comparable surfaces and distance structure; there is finding the probable
Projected Pace, then searching other horses entire PPs for a line which pits them against that pace or shows them running in a typical position against such pace (i.e.
visual Match Up); there is picking the
best 3 PoH TE's from entire PPs; there is picking the
best Early Energy style (e.g. using E/L) from lightly raced
maidens; and likely several more distinct ones or flavours of the above.
People can win and lose different races by consistently employing different paceline selections - but end up with a profit none-the-less. In my view - there are definitely rules - the rules of your adopted or created method. The rules must be almost rigorous enough that they could be coded in a computer program. Which method to use? Try them - see which suit you, which profit for you. Some people work
dozens of races a day, really quickly choosing lines from fairly mechanical approaches. Perhaps they bet superfectas or Pick 3s, while someone else bets Win only. Such a person cannot spend too much time analysing the deep possibilities in each race. They may also work 10 races and hold out for odds such that they typically bet 2 or 3 of them only. Or work 40 races to get 8 bets. Someone else may focus in great detail on just one card per day (or per weekend), and seek 5 or 10 different bets from just one card so they want to understand deeply what is going on in each race's matchup.
This all stems from differences in people's personalities and personal histories, and RDSS (or the entire Methodology as I see it) enforces no required way of going about this - only exhorting one to be
serious and develop something which
works - since it
does work! That's why you can choose your own lines in RDSS (even while you may eventually make use of an automated or semi-automated strategy to do some of the heavy lifting).
If someone (e.g. someone new) asks me my advice, I would now say investigate not the best/not the worst (if possible) from comparable distance structures and surfaces within the last 3 lines PERIOD, erring on the side of last line for recent races i.e. within 28 days (for the reasons For the Lead elaborated earlier). Be cautious of blindly using a horse's best ever effort recently (unless, perhaps, a lightly raced young horse with a recent obvious improvement vector). Too many things can go wrong demanding a horse duplicate its best ever, especially if it has just done so recently. This approach (like several of the above itemized paceline selection strategies) can be fairly well automated (which I have been doing, the past few months) in the interests of applying a
consistent approach.
For the record, re the initial example, I would choose the 3rd line (not the best, not the worst SR from the last 3 lines). I would always check to see if the energy disbursement pattern of a candidate line (check E/L readout) is reasonably consistent with how a horse typically gives its energy on a similar surface/distance structure (i.e. no use using the ONLY line in an entire career with an Early side, when EVERY other line shows somewhat Late - the Early type line is atypical, so choose a different one as more likely to represent the horse today).
My 2 cents...
Ted