Why opening prices can change more
Early limits may be lower and information may be incomplete. Operators can use the opening period to learn from market response and adjust assumptions.
A move away from an opener does not automatically mean the first number was a mistake. The information set and market conditions may simply have changed.
What the closing price contains
Near start time, confirmed participants, late availability news and a larger amount of market activity may be reflected. This can make the closing line a useful historical benchmark.
It is still affected by margin, operator-specific demand and settlement terms. Closing prices across different operators are not always identical.
Avoid hindsight bias
After a match, it is tempting to treat movement toward the winner as proof that the market knew the result. That ignores the many moves that do not align with the eventual outcome.
Evaluate the quality of a price before the event using information available at that moment. Do not rewrite the reasoning after the result.
Build an auditable odds history
Store the operator, exact market, captured time, opening definition and closing definition. Without consistent data, a closing-line comparison can become marketing rather than analysis.
Historical benchmarking should support learning, not claims of guaranteed future profit.