Decoding Bangladesh SIR data: 49 of 123 edges in closer focus

This does not mean the results will change. It just means that the deletion count is large enough compared to the margin to be electorally meaningful.All of these 49 supplemental deletion pressure seats are already within the larger 123 net deletion pressure seats.

These numbers are important because they prevent the debate from becoming blurry. Across 65 seats, the net deletions are not only greater than the net reductions, they are also greater than the net reductions. That’s more than double the profit. Across 20 seats, the gap is more than five times greater. Even through the narrower supplemental deletion test, 23 seats exceeded the 2x mark and 10 seats exceeded the 5x mark.This is not a clerical footnote.Take Rajarhat New Town as an example. The BJP won by just 316 votes. The net number of deletions was 50,274. There were 24,132 additions and deletions alone. After supplementary inspection, the deletion amount exceeded 76 times the margin; through the net deletion test, it was more than 159 times the margin.In Satgachhia, the BJP’s advantage is 401 against a net deletion of 17,783 and a supplementary deletion of 8,785. In Kashipur-Belgazia, the BJP won by 1,651 votes, with a net loss of 39,278.These numbers do not suggest that results will change. They said the number of deletions was too large to ignore.But the story here is more interesting than partisan talk. High deletion pressure does not always mean a victory for the BJP.Look at Samserganj. TMC won by 7,587 votes. Congress comes second. The net number of deletions was 83,662. There were 74,775 supplementary deletions alone, almost 10 times the number of marginals. This would not be the case in Samserganj if the pressure to remove it automatically translated into the interests of the BJP.So the more acute political issues go beyond expungement. The question is whether the vote shares in these seats also fluctuated wildly. Is the Bharatiya Janata Party on the rise? Has TMC fallen sharply? Do deleted edge maps overlap with political swing maps?The clean benchmark comes from the direct transfer of 129 seats from TMC in 2021 to the BJP in 2026. In these seats, the BJP’s average vote share increased by 10.63 percentage points on an adjusted basis, while the TMC’s average fell by 8.90 percentage points. The average two-way churn rate is 19.53 points.The strongest signal of attrition comes from the overlap between the top 50 seats gained by the BJP and the top 50 lost seats by the TMC, both in percentage terms. 35 constituencies appeared in both lists. Among them, the BJP gained an average of 15.93 points, while the TMC fell by 12.35 points. That was the real churning zone, where the rise of the BJP and the decline of the TMC happened simultaneously.This is important because 123 abridged marginal seats is not a type of politics.

Some are convertible seats for the BJP, where deletion pressure and churn occurred simultaneously. Some are TMC erosion of seats, and the beneficiary is not always the BJP. Some were pressure seats that only counted, removing seats beyond the limit, but the changes in vote share were not dramatic.Babanipur is a good example of the first type. It is not part of the 49-seat supplementary deletion pressure list. Supplementary deletion there is smaller than the margin. But the broader net deletion was 2.66 times margin. At the same time, the vote share of the BJP increased by 17.86 percentage points, while the TMC’s vote share fell by 15.52 percentage points.Therefore, Babanipur is not a story of deleted verdicts. This is a story of network deletion and loss.A similar story is told in Jadavpur. The net deletion amount is 1.25 times the deposit. Supplementary deletions are minimal. But the vote share of the BJP increased by 21.29 points while the TMC fell by 11.58 points. Jadavpur is not in the replenishment core, but it is part of a broader picture of edge removal and churn.However, Nandigram is different. Technically, it falls into the net removal pressure zone, but just right. The BJP won by 9,665 votes. Net removals were 9,891, just 226 more than profits. Supplemental deletion does not cross the line. The vote share of the Bharatiya Janata Party increased by only 1.88 percentage points. TMC fell 1.09 points.There are also different political types among the 49 supplementary pressure seats.

Some of these seats are clear seats for the BJP to surge. For example, Jangipur’s supplementary deletion was more than triple, with the BJP rising by 20.73 points and the TMC falling by 30.88 points. Rajarhat New Town, Kashipur-Belgachhia, Manikchak and Monteswar also fall into this stronger category: deletions crossed the line, with the BJP rising sharply and the TMC falling sharply.But another group told a different story. Farakka, Raninagar, Lalgola, Raghunathganj, Mothabari, Suti and Samserganj show the erosion of TMC under high missing pressure, but the beneficiaries are not always the BJP. In parts of Murshidabad and Malda, Congress and local competitive structures are important. A fall in TMC votes does not necessarily lead to a rise in votes for the BJP.And then there’s a third bucket. Raina, Pandabeswar and Jangipara have higher deletion rates and margins, but the BJP-TMC has weaker attrition rates. Pandabeswar is particularly useful as a warning. The BJP won with a margin of over four times, but the TMC’s vote share actually rose by 0.29 percentage points. This cannot be called anti-TMC seat loss.On a smaller scale, especially in Kolkata and adjacent areas of the city, marginal pressure overlaps with the sharp rise of the BJP and the sharp decline of the TMC.Therefore, there is no clear way to say that the seats most affected by SIR disproportionately helped one party. At a micro level, it roughly reflects the prevailing situation in the constituency. SIR has the word “special” in its name, but its results aren’t statistically obnoxious. What stands out is the math of the profits it leaves behind.