todds1 / todds0 / todds2 fields are the devig odds (margin removed logarithmically) — the fair probabilities.
They are present on every snapshot of /api/odds (not only opening/closing), which lets you track how the edge evolves over time.
Detecting value (+EV)
Compare a bookmaker’s odds to thetodds. If a book offers odds higher than the corresponding todds, it is a positive expected value opportunity.
Since Pinnacle is the sharpest book, its devig odds are your OTB (Odds To Beat) — the reference for identifying value and computing CLV.
Specials & outrights
/api/specials/odds also includes a todds field on each line. All contestants of a special are devig together (2-way or N-outcome market).
CLV
Use/api/clv to compare your bet price to the closing price and get the clv_pct: