A system name is not a complete aiming instruction. When a lesson is called Conti, first identify its diagram, reference stroke and arrival convention. Combining numbers from two versions can produce a plausible calculation with the wrong target.
What the reference actually shows
The linked Sancho Standard document describes its relationship to Hoppe and Conti and then presents its own method. It is evidence for that documented version, not proof that every lesson called Conti uses identical numbering. Its diagrams distinguish departure and attack lines through frame marks from arrivals at the cushion nose.
A mark on the wooden frame and the point directly in front of it on the cushion are different targets on an oblique line. Keep the original diagram visible while reading the values. Do not move a number to another rail because its physical spacing looks similar.
Check the arithmetic without claiming a route
For a chart using arrival = departure − attack, 50 − 15 = 35 is an arithmetic example. It predicts a physical arrival only if all three values were read using that chart’s scales and valid shot family. It does not mean “start at physical diamond 50”.
Record which contact the arrival represents. A third-cushion value cannot be copied onto the fourth cushion: the next leg has its own geometry and, in the reference, separate corrections.
A comparison sheet you can use
Choose one clearly illustrated reference line. Record the chart page, cue-ball location, frame or nose aim, stroke and expected third-cushion contact. Repeat the same setup and record the observed contact and its spread before changing anything.
If the spread is wide, work on reproducing the setup and stroke. If it is narrow but displaced, check the numbering convention first, then investigate the table-specific adjustment. Change one input at a time. This separates a reading error from an execution or table-response problem.
When to put the chart aside
A blocked first leg, a kiss risk or an unsuitable route family can make a numerically convenient line unusable. Compare a different legal route rather than forcing an unsupported correction. A simulator can help inspect geometry; it does not certify that a printed table will reproduce on your cloth.