Excessive unsuccessful bids (R025)

The ratio of winning bids to submitted bids for a top tenderer is a low outlier.


For each tenderer, the ratio is calculated as \(numberOfWinningBids \over numberOfValidBids\) across all contracting processes.

A tenderer is flagged if:

  • Its number of valid bids is greater than or equal to the upper fence of the third quartile (\(Q_3\)) of the set of numbers of valid bids.

  • Its ratio is less than or equal to the lower fence of \(Q_1 - 1.5(IQR)\), where \(Q_1\) is the first quartile and \(IQR\) is the interquartile range for the set of ratios.


75% (\(Q_3\)) of bidders in Atlantis submitted at most 100 bids. UnethicalBid Ltd. submitted 150 bids. This is greater than the upper fence of 100. Therefore, UnethicalBid Ltd. is a top tenderer.

25% (\(Q_1\)) of bidders in Atlantis won at most half (0.5) of their bids. 75% (\(Q_3\)) of bidders won at most three quarters (0.75) of their bids. This yields a lower fence of one eighth (0.125).

UnethicalBid Ltd. won 15 of its 150 bids, or one tenth (0.1). This is less than the lower fence of one eighth. Therefore, UnethicalBid Ltd. is flagged.

Why is this a red flag?

A colluding bidder can mimic competition by submitting deliberately losing bids (at inflated bid prices, for example) in contracting processes in which a colluding partner participates.

Based on “Superfluous losing bidders” in Toolkit for detecting collusive bidding in public procurement and “Top losers” in A decision support system for fraud detection in public procurement.


The indicator’s value is the ratio, as a decimal.


All configuration is optional.

To override the default upper fence, add to your settings file, as a percentage:

percentile = 75 # default

To override the default lower fence, add to your settings file, as a decimal:

threshold = 0.05


Put all properties under one [R025] section.


A contracting process is excluded if:

  • An award’s status is pending or invalid.

  • There are multiple active awards (a.k.a. winning bids). #14

  • A bid is submitted by multiple tenderers. #17

  • An award is made to multiple suppliers. #17


Do you want to eliminate an exclusion? Please contributed to the linked GitHub issue.





$ ocdscardinal indicators --settings docs/examples/R/025.ini --no-meta docs/examples/R/025.jsonl