Decoding Bengal SIR data: Of 123 margins, 49 in closer focus

Special Intensive Revision (SIR) was decidedly the biggest talking constituent of the West Bengal election. The last effect was thing abbreviated of a governmental earthquake, with BJP winning 207 seats, surpassing astir expectations, the mighty TMC humbled to 80, and different parties reduced to a specified footnote.The anti-incumbency was truthful acute that it astir apt blew distant overmuch of the discomfort and choler astir SIR, which TMC had wanted to leverage, galore pundits believe. Some person antecedently argued that the deletions were done successful a politically motivated mode to tilt the likelihood successful BJP’s favour, particularly pointing to the “logical discrepancy” origin introduced precocious successful the SIR process.Here, we decode the information based connected antithetic thresholds.To recognize the imaginable effect of SIR, the astir evident starting constituent is to cheque the seats wherever elector deletions were larger than the borderline by which the spot was won.This investigation uses constituency-wise deletion calculations by Sabar Institute, mapped with the 2026 result-margin data. Net deletion present means deletions for reasons different than death. The net-deletion array covers 294 Assembly constituencies and adds up to 66,62,010 deletions.

And this is wherever the archetypal large fig comes in.In 123 of Bengal’s 293 declared seats, nett deletion was larger than the winning margin. BJP won 83 of these seats, TMC 38, and Congress 2. BJP’s tally of 83 retired of 123 is astir two-thirds, broadly successful the aforesaid portion arsenic its wide dominance successful the election.There is simply a second, sharper layer. Supplementary deletion, from the supplementary/adjudication layer, crossed the triumph borderline successful 49 seats.

This refers to under-adjudication voters whose names were yet deleted. At last count, 27.16 lakh of the astir 60 lakh under-adjudication names were deleted. When mapped constituency-wise, BJP won 26 of these 49 seats, TMC 21, and Congress 2.For clarity, we are utilizing the connection accent successful a constrictive arithmetical sense. A spot is counted arsenic a deletion-stress spot erstwhile the fig of deletions is larger than the triumph margin.

So if a constituency was won by 5,000 votes and nett deletion was 12,000, that spot enters the accent database due to the fact that deletion was much than doubly the margin.

This does not mean the effect would person changed. It lone means the deletion number was ample capable to beryllium electorally worldly erstwhile compared with the margin.All these 49 supplementary-deletion accent seats were already wrong the larger 123-seat net-deletion accent universe.

These numbers substance due to the fact that they halt the statement from becoming vague. In 65 seats, nett deletion was not conscionable larger than the margin; it was much than treble the margin. In 20 seats, it was much than 5 times the margin. Even by the narrower supplementary-deletion test, 23 seats crossed the 2x people and 10 seats crossed the 5x mark.That is not a clerical footnote.Take Rajarhat New Town. BJP won by conscionable 316 votes. Net deletion determination was 50,274.

Supplementary deletion unsocial was 24,132. By the supplementary test, deletion was much than 76 times the margin; by the net-deletion test, it was much than 159 times the margin.In Satgachhia, BJP’s borderline was 401, portion nett deletion was 17,783 and supplementary deletion was 8,785. In Kashipur-Belgachhia, BJP won by 1,651, portion nett deletion stood astatine 39,278.These numbers bash not accidental the effect would person changed.

They accidental the deletion fig was acold excessively ample to ignore.But present is wherever the communicative becomes much absorbing than a partisan talking point. High deletion accent did not ever mean a BJP win.Look astatine Samserganj. TMC won by 7,587 votes. Congress came second. Net deletion was 83,662. Supplementary deletion unsocial was 74,775, astir 10 times the margin. If deletion accent automatically translated into BJP benefit, Samserganj would not look similar this.The sharper governmental question, therefore, is not simply wherever deletions crossed margins. It is whether these seats besides saw crisp vote-share churn. Did BJP emergence sharply? Did TMC autumn sharply? Did the deletion-margin representation overlap with the governmental plaything map?The cleanable benchmark comes from the 129 seats that moved straight from TMC successful 2021 to BJP successful 2026. In these seats, BJP’s mean vote-share summation was 10.63 percent points connected the adjusted basis, portion TMC’s mean autumn was 8.90 points.

The mean two-way churn was 19.53 points.The strongest churn awesome comes from the overlap of the apical 50 BJP-gain seats and the apical 50 TMC-drop seats, some measured successful percentage-point terms. Thirty-five constituencies look successful some lists. In these, BJP gained 15.93 points connected average, portion TMC fell 12.35 points. That is the existent churn zone, wherever BJP’s emergence and TMC’s autumn happened together.This matters due to the fact that the 123 deletion-margin seats are not 1 governmental type.

Some are BJP-conversion seats, wherever deletion accent and churn moved together. Some are TMC-erosion seats wherever the beneficiary was not ever BJP. Some are arithmetic-only accent seats, wherever deletion crossed the borderline but the vote-share question was not dramatic.Bhabanipur is simply a bully illustration of the archetypal type. It is not portion of the 49-seat supplementary-deletion accent list. Supplementary deletion determination was smaller than the margin.

But broader nett deletion was 2.66 times the margin. At the aforesaid time, BJP’s ballot stock roseate 17.86 percent points, portion TMC’s fell 15.52 points.So Bhabanipur is not an adjudication-deletion story. It is simply a net-deletion-plus-churn story.Jadavpur tells a akin story. Net deletion was 1.25 times the margin. Supplementary deletion was small. But BJP’s ballot stock jumped 21.29 points, portion TMC fell 11.58 points.

Jadavpur is not successful the supplementary core, but it is precise overmuch portion of the broader deletion-margin and churn map.Nandigram, however, is different. It technically falls into the net-deletion accent zone, but lone just. BJP won by 9,665. Net deletion was 9,891, conscionable 226 much than the margin. Supplementary deletion did not transverse the margin. BJP’s vote-share summation was lone 1.88 points. TMC’s autumn was 1.09 points.Inside the 49 supplementary-stress seats too, determination are antithetic governmental types.

Some are wide BJP-surge seats. Jangipur, for instance, shows supplementary deletion much than 3 times the margin, BJP gaining 20.73 points, and TMC falling 30.88 points. Rajarhat New Town, Kashipur-Belgachhia, Manikchak and Monteswar besides autumn into this stronger bucket: deletion crossed the margin, BJP roseate sharply, and TMC fell sharply.But different acceptable tells a antithetic story. Farakka, Raninagar, Lalgola, Raghunathganj, Mothabari, Suti and Samserganj amusement TMC erosion nether precocious deletion stress, but the beneficiary was not ever BJP.

In parts of Murshidabad and Malda, Congress and section contention operation mattered. A falling TMC ballot did not ever go a rising BJP vote.Then determination is simply a 3rd bucket. Raina, Pandabeswar and Jangipara had precocious deletion-to-margin ratios, but anemic BJP-TMC churn. Pandabeswar is particularly utile arsenic a warning. BJP won and supplementary deletion was much than 4 times the margin, but TMC’s ballot stock really roseate by 0.29 points.

That cannot beryllium called an anti-TMC churn seat.In a smaller set, particularly successful Kolkata and urban-adjacent belts, borderline accent overlapped with a crisp BJP emergence and a crisp TMC fall.Hence, determination is nary definitive mode to say, seats worst affected by SIR disproportionately helped a definite governmental party. It broadly mirrored the prevailing crushed concern astatine that fixed constituency erstwhile looked astatine a micro level. SIR had “special” successful its name, but the effect did not instrumentality retired arsenic a statistical sore thumb. What stood retired was the borderline mathematics it near behind.