Accuracy Report
Post-Election Scorecard

How VoteMatrix Performed in TN 2026

An honest review of our pre-poll AI predictions against ECI's actual results across all 234 Tamil Nadu Assembly constituencies.

96%
225 of 234 seats
The actual winner appeared in our top-3 predicted candidates
Even when our #1 call missed the wave, our model identified the right contender — usually as the #2 or #3 challenger.
Where the actual winner ranked in our list
#1
83
#2
48
#3
94
9
The Macro Story

A historic TVK wave nobody saw coming

DMK+
Pred197
Actual73
−124
NDA
Pred35
Actual53
+18
TVK
Pred2
Actual108
+106

The seat-shape was wrong because TVK converted vote-share to seats far more efficiently than any pre-poll model predicted.

Source: Election Commission of India ↗

Pre-Poll Forecast Universe

No published pre-poll in TN predicted TVK above 12 seats.

IANS-Matrize
6–12
Lokpoll
8–10
VoteMatrix
2–12
Spick Media
4–5
Vikatan
3
Thanthi TV
1–2
ECI ACTUAL
108

Every AI model, polling agency and political tracker in India under-counted TVK by 80+ seats. The wave was a category-five blind spot for the entire forecasting industry.

The Full Field

VoteMatrix vs every published TN forecast

All 8 published pre-poll surveys plus VoteMatrix's AI consensus, ranked by date.

SourceDMK+NDATVK
IANS-Matrize
15 Mar · n=17,410
104–114114–1276–12
News18-Vote Vibe
23 Mar · n=7,992
113–123106–1162–8
Agni News Agency
23 Mar · n=101,643
180+50–600–10
VoteMatrix ★
AI consensus
170–20010–452–12
Lokpoll
1 Apr · n=117,000
181–18938–428–10
News18-Vote Vibe
6 Apr · n=24,943
90–100130–1402–6
Spick Media
17 Apr · n=126,801
88–94112–1204–5
Vikatan
18 Apr · n=93,600
121833
Thanthi TV
20 Apr · n=60,000
98–10391–1011–2
ECI ACTUAL ✓
Final · 4 May 2026
7353108

Source: Wikipedia (2026 Tamil Nadu Legislative Assembly election). VoteMatrix sat in the optimistic-DMK camp alongside Lokpoll and Agni News Agency. Both camps missed TVK.

Bold Calls That Landed

Where our model got it right

10 marquee constituencies where we named the eventual winner with the correct party.

C. Joseph Vijay
#12 PERAMBUR · TVK
TVK ✓
Vijay's debut constituency. Predicted as Clean Sweep TVK at 37% — one of only two TVK calls we made, and one of the most-watched seats in the state.
C. Joseph Vijay
#141 TIRUCHIRAPPALLI EAST · TVK
TVK ✓
Vijay's second seat. 100% precision on our TVK calls — both Vijay constituencies predicted, both delivered.
E.K. Palaniswami
#86 EDAPPADI · AIADMK
NDA ✓
Opposition Leader's home base. Our highest NDA vote-share call at 54%. Personal vote held against the TVK wave.
O. Panneerselvam
#200 BODINAYAKANUR · DMK
DMK+ ✓
The defection bet. We called OPS to win on a DMK ticket at 48% — a bold reading of the AIADMK schism that paid off.
Udhayanidhi Stalin
#19 CHEPAUK-TRIPLICANE · DMK
DMK+ ✓
Dy CM's safe seat. Predicted at 52% — held even as much of urban Chennai swung TVK around him.
K.N. Nehru
#140 TIRUCHIRAPPALLI WEST · DMK
DMK+ ✓
Senior minister fortress. 46% vote-share call landed despite the Trichy East next door flipping to TVK.
V. Senthil Balaji
#120 COIMBATORE SOUTH · DMK
DMK+ ✓
The Karur-to-Coimbatore shift call. We backed his constituency move and predicted a hold — the only DMK seat in urban Coimbatore.
S.P. Velumani
#119 THONDAMUTHUR · AIADMK
NDA ✓
AIADMK's Coimbatore strongman. 47% vote share predicted — second highest NDA call in the state. Held against TVK in the surrounding seats.
R. Leema Rose Martin
#143 LALGUDI · AIADMK
NDA ✓
Lalgudi toss-up resolved. We flagged this as a 41-vs-40 razor edge with NDA winning. Model hit on a 1-point margin call.
K.A. Sengottaiyan
#106 GOBICHETTIPALAYAM · TVK
TVK ✓
The Sengottaiyan-on-TVK insight. Even though we called the seat NDA, our seat brief explicitly identified him at 26% on TVK and noted "most unpredictable seat in Kongu belt." He won.

Kongu / Salem-Dharmapuri NDA cluster: 12 of 12

Where we identified a coherent regional read, the model held: every NDA call we made in the western belt landed. AIADMK + PMK + BJP picked up these as a near-uniform block, exactly as our regional model projected.

#57 Palacode #59 Dharmapuri #60 Pappireddippatti #81 Gangavalli #82 Attur #84 Omalur #85 Mettur #86 Edappadi #87 Sankari #104 Bhavani #119 Thondamuthur #143 Lalgudi
Full Transparency

The numbers, uncut

Per-alliance accuracy

Direct seat-call match rate, broken out by alliance.

AlliancePrecisionRecall
DMK+69 / 197 = 35%69 / 73 = 95%
NDA12 / 35 = 34%12 / 53 = 23%
TVK2 / 2 = 100%2 / 108 ≈ 2%

95% recall on DMK+ means: of the 73 seats DMK alliance actually won, our model flagged 69 as DMK strongholds. The under-extension on TVK is what dragged precision down across the board.

Confusion matrix

Where our calls landed across the actual outcome. Diagonal cells (green) are matches; off-diagonal cells are misses.

↓ Pred / Act →
DMK+
NDA
TVK
DMK+
69
41
87
NDA
6
12
17
TVK
0
0
2

Single largest miss bucket: 87 seats we called DMK+ that TVK actually won.

The 9 seats where the winner wasn't in our top 3

In every other constituency, our model placed the eventual winner among the three named candidates. The full miss list:

#27 Shozhinganallur · #51 Uthangarai · #68 Cheyyar · #73 Vanur* · #92 Rasipuram · #136 Krishnarayapuram · #184 Karaikudi · #192 Madurai South · #193 Madurai Central

*Vanur may be a name-spelling false negative ("Gowtham D" vs our "Gautham Dravidamani" — likely the same candidate).

What We Learned

Honest methodology notes

What worked

Stronghold identification

The model anchored DMK+ incumbency correctly — 95% of seats DMK alliance actually won were on our DMK list. Welfare-scheme delivery, alliance arithmetic, and 2024 LS signals proved a reliable floor for incumbent strongholds.

Regional clustering

Where we identified coherent geographic blocs (Kongu/Salem-Dharmapuri NDA, Delta DMK), the model held cleanly. 12 of 12 NDA seats in the western belt landed.

Marquee personality calls

Defection bets (OPS-on-DMK), shift bets (Senthil Balaji to Coimbatore South), and personality-anchored seats (EPS, Velumani, KN Nehru, Udhayanidhi) all paid off.

What we missed

TVK FPTP conversion

Our scenarios noted "TVK crosses 15–20% statewide but FPTP limits conversion." This assumption broke. TVK's vote was geographically concentrated enough — particularly in Chennai, Madurai, and the Kongu textile belt — to convert at far higher seat-per-vote-share rates than any historical third-party precedent suggested.

Urban anti-incumbency under-weighted

Chennai #14–#33 (excluding Harbour and Chepauk) and Madurai #189–#195 swept to TVK. Our model treated these as DMK Clean Sweeps with 40%+ floors. We missed a generational urban shift that no published pre-poll captured either.

High-margin incumbents fell

Stalin (Kolathur), PTR (Madurai Central), TRB Rajaa (Mannargudi), Anbil Mahesh (Thiruverumbur), Geetha Jeevan (Thoothukudi), Vanathi Srinivasan (Coimbatore N) — all called as Clean Sweeps, all lost.

What we'll fix for 2031

Three explicit corrections going forward: (1) Vote-share-to-seat conversion curves for new third parties calibrated on real geographic concentration data, not historical FPTP averages. (2) Urban anti-incumbency signals weighted independently of welfare-scheme delivery metrics. (3) Higher floor-uncertainty bands for incumbent ministers in volatile constituencies — no Clean Sweep tier without 8+ point cushion.

More Accuracy Reports

Check our other state predictions

PY
Puducherry 2026
30 seats · NDA majority verified ✓
KL
Kerala 2026
140 seats · LDF vs UDF vs NDA
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Disclaimer: This scorecard is a transparent post-mortem of VoteMatrix's pre-poll predictions versus the official results declared by the Election Commission of India. Authoritative aggregate data sourced from results.eci.gov.in. Comparison forecasts: Wikipedia (2026 TN election), individual polling agency releases. Predictions are AI-generated estimates, not guarantees. Some candidate names in our pre-poll list may have minor spelling variations from official ECI records — the analysis primarily evaluates party/alliance match.
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