diff --git a/.gitignore b/.gitignore
index 392691f..e0817fd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -23,3 +23,7 @@ go.work.sum
 # OS
 .DS_Store
 Thumbs.db
+
+# Python bytecode from the benchmark harness
+__pycache__/
+*.pyc
diff --git a/bench/go.mod b/bench/go.mod
index f592b91..e3dfbdb 100644
--- a/bench/go.mod
+++ b/bench/go.mod
@@ -8,4 +8,18 @@ go 1.25.0
 
 require github.com/hallelx2/pdftable v0.0.0
 
+require (
+	github.com/clipperhouse/uax29/v2 v2.7.0 // indirect
+	github.com/hhrutter/lzw v1.0.0 // indirect
+	github.com/hhrutter/pkcs7 v0.2.2 // indirect
+	github.com/hhrutter/tiff v1.0.3 // indirect
+	github.com/mattn/go-runewidth v0.0.23 // indirect
+	github.com/pdfcpu/pdfcpu v0.12.1 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
+	golang.org/x/crypto v0.50.0 // indirect
+	golang.org/x/image v0.39.0 // indirect
+	golang.org/x/text v0.36.0 // indirect
+	gopkg.in/yaml.v2 v2.4.0 // indirect
+)
+
 replace github.com/hallelx2/pdftable => ../
diff --git a/bench/go.sum b/bench/go.sum
new file mode 100644
index 0000000..eb36f86
--- /dev/null
+++ b/bench/go.sum
@@ -0,0 +1,24 @@
+github.com/clipperhouse/uax29/v2 v2.7.0 h1:+gs4oBZ2gPfVrKPthwbMzWZDaAFPGYK72F0NJv2v7Vk=
+github.com/clipperhouse/uax29/v2 v2.7.0/go.mod h1:EFJ2TJMRUaplDxHKj1qAEhCtQPW2tJSwu5BF98AuoVM=
+github.com/hhrutter/lzw v1.0.0 h1:laL89Llp86W3rRs83LvKbwYRx6INE8gDn0XNb1oXtm0=
+github.com/hhrutter/lzw v1.0.0/go.mod h1:2HC6DJSn/n6iAZfgM3Pg+cP1KxeWc3ezG8bBqW5+WEo=
+github.com/hhrutter/pkcs7 v0.2.2 h1:xMoifoVWah1LNym3C0pomEiLmyJyVIBXt/8oTPyPz+8=
+github.com/hhrutter/pkcs7 v0.2.2/go.mod h1:aEzKz0+ZAlz7YaEMY47jDHL14hVWD6iXt0AgqgAvWgE=
+github.com/hhrutter/tiff v1.0.3 h1:POV5xITOE1Lt5FvP24ylft0LyCmHmc8GkJ1SVlvUyk0=
+github.com/hhrutter/tiff v1.0.3/go.mod h1:zZDLVY4cp9za2FLrryAaGszwWYAUM6DrRiBR0l//mxA=
+github.com/mattn/go-runewidth v0.0.23 h1:7ykA0T0jkPpzSvMS5i9uoNn2Xy3R383f9HDx3RybWcw=
+github.com/mattn/go-runewidth v0.0.23/go.mod h1:XBkDxAl56ILZc9knddidhrOlY5R/pDhgLpndooCuJAs=
+github.com/pdfcpu/pdfcpu v0.12.1 h1:HwoN72zJCj+pPbfMDChYBTZrT7SY0VwgUzqeaId3I20=
+github.com/pdfcpu/pdfcpu v0.12.1/go.mod h1:7KPpVLMavcpliPrtN6o7Kuk3cFtYq8nii3SJnnsK7ps=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+golang.org/x/crypto v0.50.0 h1:zO47/JPrL6vsNkINmLoo/PH1gcxpls50DNogFvB5ZGI=
+golang.org/x/crypto v0.50.0/go.mod h1:3muZ7vA7PBCE6xgPX7nkzzjiUq87kRItoJQM1Yo8S+Q=
+golang.org/x/image v0.39.0 h1:skVYidAEVKgn8lZ602XO75asgXBgLj9G/FE3RbuPFww=
+golang.org/x/image v0.39.0/go.mod h1:sIbmppfU+xFLPIG0FoVUTvyBMmgng1/XAMhQ2ft0hpA=
+golang.org/x/text v0.36.0 h1:JfKh3XmcRPqZPKevfXVpI1wXPTqbkE5f7JA92a55Yxg=
+golang.org/x/text v0.36.0/go.mod h1:NIdBknypM8iqVmPiuco0Dh6P5Jcdk8lJL0CUebqK164=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
+gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
diff --git a/bench/icdar2013/__pycache__/score.cpython-313.pyc b/bench/icdar2013/__pycache__/score.cpython-313.pyc
deleted file mode 100644
index 678893b..0000000
Binary files a/bench/icdar2013/__pycache__/score.cpython-313.pyc and /dev/null differ
diff --git a/bench/icdar2013/extract.go b/bench/icdar2013/extract.go
index 255cd04..a6f7cac 100644
--- a/bench/icdar2013/extract.go
+++ b/bench/icdar2013/extract.go
@@ -6,6 +6,7 @@ import (
 	"flag"
 	"fmt"
 	"os"
+	"strconv"
 
 	"github.com/hallelx2/pdftable"
 )
@@ -15,9 +16,18 @@ type tableOut struct {
 	Rows [][]string `json:"rows"`
 }
 
+// edgeSet is one page's explicit row/column boundaries, in PDF points.
+type edgeSet struct {
+	V []float64 `json:"v"`
+	H []float64 `json:"h"`
+}
+
 func main() {
-	strategy := flag.String("strategy", "lines", "lines | text | fallback")
+	strategy := flag.String("strategy", "lines",
+		"lines | text | mixed | auto | lines-then-mixed | fallback")
 	merge := flag.Bool("merge", false, "TableSettings.MergeSplitTokens")
+	oracle := flag.String("oracle", "",
+		`JSON of per-page explicit edges: {"1":{"v":[..],"h":[..]}}`)
 	flag.Parse()
 
 	doc, err := pdftable.OpenFile(flag.Arg(0))
@@ -38,27 +48,37 @@ func main() {
 	}
 	lines := mk(pdftable.StrategyLines, pdftable.StrategyLines)
 	text := mk(pdftable.StrategyText, pdftable.StrategyText)
-
 	// "mixed" is the booktabs case: horizontal rules give the rows, word
-	// alignment gives the columns. A table ruled only horizontally has no
-	// ruling intersections at all, so pure "lines" cannot see it.
+	// alignment gives the columns.
 	mixed := mk(pdftable.StrategyText, pdftable.StrategyLines)
 	auto := mk(pdftable.StrategyAuto, pdftable.StrategyAuto)
 
 	var attempts []pdftable.TableSettings
 	switch *strategy {
-	case "lines":
-		attempts = []pdftable.TableSettings{lines}
 	case "text":
 		attempts = []pdftable.TableSettings{text}
 	case "mixed":
 		attempts = []pdftable.TableSettings{mixed}
-	case "lines-then-mixed":
-		attempts = []pdftable.TableSettings{lines, mixed}
 	case "auto":
 		attempts = []pdftable.TableSettings{auto}
-	default: // fallback: ruled cells first, whitespace alignment if none
+	case "lines-then-mixed":
+		attempts = []pdftable.TableSettings{lines, mixed}
+	case "fallback":
 		attempts = []pdftable.TableSettings{lines, text}
+	default:
+		attempts = []pdftable.TableSettings{lines}
+	}
+
+	// Oracle mode: the caller supplies the row/column boundaries and
+	// pdftable only fills the cells. This is exactly the shape of the
+	// hybrid a layout model would drive — and fed GROUND-TRUTH edges it
+	// measures the ceiling that hybrid can reach: how good extraction gets
+	// if detection and gridding were solved perfectly.
+	var oracleEdges map[string]edgeSet
+	if *oracle != "" {
+		if b, err := os.ReadFile(*oracle); err == nil {
+			_ = json.Unmarshal(b, &oracleEdges)
+		}
 	}
 
 	out := []tableOut{}
@@ -67,6 +87,23 @@ func main() {
 		if err != nil {
 			continue
 		}
+
+		if oracleEdges != nil {
+			e, ok := oracleEdges[strconv.Itoa(i)]
+			if !ok || len(e.V) < 2 || len(e.H) < 2 {
+				continue
+			}
+			s := mk(pdftable.StrategyExplicit, pdftable.StrategyExplicit)
+			s.ExplicitVerticalLines = e.V
+			s.ExplicitHorizontalLines = e.H
+			if tables, err := p.ExtractTables(s); err == nil {
+				for _, t := range tables {
+					out = append(out, tableOut{Page: i, Rows: t.Rows})
+				}
+			}
+			continue
+		}
+
 		for _, s := range attempts {
 			tables, err := p.ExtractTables(s)
 			if err != nil || len(tables) == 0 {