diff --git a/CHANGELOG.md b/CHANGELOG.md
index 13d806e3..57717328 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -33,6 +33,10 @@ APIs change between minors without a deprecation period.
   which a judge never reuses: each text it reads is different. On a 4-core, 8 GB machine the second judge then fitted
   nowhere ("has 7 GB of memory with 1 free, needs 4"). The judge now runs with `--cache-ram 0`, uses about 1.6 GB and
   stays there, and reserves 2.
+- **One machine runs one judge, on up to four cores.** A second replica on the same machine shares its cores and is
+  lost with it, so it bought nothing but half the speed of each. `server init` on a single machine now serves one judge
+  on up to four cores (2.3 s a judgment where two on two cores took 4.2). Where there will be other nodes, it serves two
+  on two cores each, as in HA setups. `--judge-replicas` and the setup's Copies still choose.
 - **A judge gets the two cores it needs.** v0.14.6 gave each judge replica one core on machines under eight. A judgment
   of about 280 tokens takes 8.0 s on one core, 4.2 s on two and 2.3 s on four, against the 5 s budget, so on a 4-core
   machine every judgment timed out and every request was refused. A judge replica now reserves two cores, one only
diff --git a/docs/install.md b/docs/install.md
index fa33a57b..f3eae0fe 100644
--- a/docs/install.md
+++ b/docs/install.md
@@ -152,9 +152,9 @@ That is the whole step. In order, it:
    `nvidia-smi` finds any, on CPU otherwise — and waits for it to install its
    engine
 9. closes llmgw's internal ports to everything but the cluster's networks
-10. fetches Qwen3Guard-Gen 0.6B, the guardrails' judge, and runs two
-    replicas on the CPUs of nodes with room — this one, or the first that
-    join ([guardrails.md](guardrails.md#a-judge-model) has one on a GPU too)
+10. fetches Qwen3Guard-Gen 0.6B, the guardrails' judge, and runs it on
+    CPUs: one replica on up to four cores when this machine is the only
+    node, two on two cores each on the nodes of a larger cluster ([guardrails.md](guardrails.md#a-judge-model) has one on a GPU too)
 11. fetches Qwen2.5 0.5B into the mirror and serves it on this node, so the
     first thing anyone opens `/chat` to find is a model that answers. A
     machine without room for it is told so within two minutes, and why.
@@ -187,15 +187,19 @@ demonstration one:
 | Requests | every key limited (60 a minute, 200 000 tokens a minute) and priced, so budgets bind |
 | Guardrails | the `baseline` policy on every request: secrets in prompts and answers refused, card numbers masked, injection attempts recorded, and the judge refusing violence, crime, weapons, child abuse, privacy violations, hate, self-harm and sexual content, in prompts and answers |
 
-The judge runs as two replicas, each on a CPU — about half a second for a
-short text on any CPU with AVX2 — and reads a streamed answer every 600
-characters. The policy fails **closed**: a request the judge cannot read
-within 5 seconds is refused with 503 rather than served unjudged, and
-`judge_unavailable` goes to the notification webhooks. Two replicas are what
-make that bearable; on one small machine, or a VM without AVX2 (see
+The judge runs on CPUs. A judgment of about 280 tokens took 2.3 s on four
+cores, 4.2 s on two and 8.0 s on one (a 4-core VM). It also reads a
+streamed answer every 600 characters. The policy fails **closed**: a request
+the judge cannot read within 5 seconds is refused with 503 rather than
+served unjudged, and `judge_unavailable` goes to the notification webhooks.
+So a judge gets cores of its own: on one machine one replica on up to four,
+and on a larger cluster two replicas of two cores each, spread over its nodes
+so that losing one leaves the other. On a machine of fewer than four cores,
+a busy one, or a VM without AVX2 (see
 [step 6](#6-setting-the-nodes-cpu-model-if-it-is-a-vm)), the judge is the
-first thing to fail, so `fail: open` — serve it, recorded as flagged — or
-`--no-guard-model` is the choice there. Defamation, specialized advice,
+first thing to fail. The choices there are a longer `latency_budget`,
+`fail: open` (serve the request, recorded as flagged), the judge on a GPU,
+or `--no-guard-model`. Defamation, specialized advice,
 intellectual property and elections are left out of what it refuses: they
 catch too much ordinary work. [guardrails.md](guardrails.md) has the rest.
 
diff --git a/internal/cli/serverinit_choices.go b/internal/cli/serverinit_choices.go
index 0b8f8cc3..4a0d6da1 100644
--- a/internal/cli/serverinit_choices.go
+++ b/internal/cli/serverinit_choices.go
@@ -194,6 +194,9 @@ func (in *serverInit) judgeFor() judgeSpec {
 	}
 	if j.Replicas <= 0 {
 		j.Replicas = 2
+		if in.singleMachine() {
+			j.Replicas = 1
+		}
 	}
 	if j.Budget <= 0 {
 		j.Budget = 5 * time.Second
@@ -201,6 +204,14 @@ func (in *serverInit) judgeFor() judgeSpec {
 	return j
 }
 
+// singleMachine is an install where this machine is the only node there
+// will be, as far as init knows: a second judge replica there shares the
+// same cores and is lost with the same machine, so it buys nothing but
+// half the speed of each.
+func (in *serverInit) singleMachine() bool {
+	return !in.noNode && !in.standbys && len(in.patroni) == 0 && len(in.patroniNodes) == 0
+}
+
 // The configuration's limits, as init writes them unless told otherwise.
 const (
 	defaultRPM       = 60
@@ -346,7 +357,10 @@ func (in *serverInit) initFlags() []string {
 	if in.noGuardModel {
 		add("--no-guard-model")
 	} else {
-		j, d := in.judgeFor(), (&serverInit{}).judgeFor()
+		// Against the defaults for an install of the same shape: one judge
+		// on one machine, two otherwise.
+		shape := serverInit{noNode: in.noNode, standbys: in.standbys, patroni: in.patroni, patroniNodes: in.patroniNodes}
+		j, d := in.judgeFor(), shape.judgeFor()
 		if j.Fail != d.Fail {
 			add("--judge-fail", j.Fail)
 		}
diff --git a/internal/cli/serverinit_choices_test.go b/internal/cli/serverinit_choices_test.go
index 31757761..3cfe47fa 100644
--- a/internal/cli/serverinit_choices_test.go
+++ b/internal/cli/serverinit_choices_test.go
@@ -183,12 +183,17 @@ func TestTheJudgesAndTheStarterShareTheCPUsRatherThanEachTakingAll(t *testing.T)
 		in             serverInit
 		judge, starter int
 	}{
-		{serverInit{cpus: 4}, 2, 0}, // two a judge, and the starter shares what is left
-		{serverInit{cpus: 8}, 2, 4},
-		{serverInit{cpus: 32}, 2, 8},
-		{serverInit{cpus: 2}, 1, 0}, // below four, one each, so both fit
+		// One machine: one judge, on up to four cores; the starter has the rest.
+		{serverInit{cpus: 4}, 4, 0},
+		{serverInit{cpus: 8}, 4, 4},
+		{serverInit{cpus: 32}, 4, 8},
+		{serverInit{cpus: 2}, 2, 0},
 		{serverInit{cpus: 1}, 0, 0},
-		{serverInit{cpus: 4, noGuardModel: true}, 2, 4},
+		{serverInit{cpus: 4, noGuardModel: true}, judgeCores, 4}, // no judge: all for the starter
+		// Two asked for on one machine: two cores each, one each where two
+		// would not fit both.
+		{serverInit{cpus: 8, judge: judgeSpec{Replicas: 2}}, 2, 4},
+		{serverInit{cpus: 2, judge: judgeSpec{Replicas: 2}}, 1, 0},
 		{serverInit{cpus: 8, judge: judgeSpec{Replicas: 3}}, 2, 2},
 		{serverInit{cpus: 4, noNode: true}, 2, 0}, // on nodes not known yet
 	} {
@@ -206,3 +211,31 @@ func TestTheJudgesAndTheStarterShareTheCPUsRatherThanEachTakingAll(t *testing.T)
 		t.Errorf("starter: GPU profile %d cores, CPU %+v", s.Profiles[0].CPUCores, cpu)
 	}
 }
+
+// A second judge on the same machine shares its cores and is lost with it:
+// one machine has one, more machines two.
+func TestOneMachineHasOneJudgeAndMoreHaveTwo(t *testing.T) {
+	for _, c := range []struct {
+		in   serverInit
+		want int
+	}{
+		{serverInit{}, 1},
+		{serverInit{noNode: true}, 2},
+		{serverInit{patroni: []string{"a@db1", "b@db2"}}, 2},
+		{serverInit{standbys: true}, 2},
+		{serverInit{judge: judgeSpec{Replicas: 3}}, 3},
+	} {
+		if got := c.in.judgeFor().Replicas; got != c.want {
+			t.Errorf("%+v: %d judges, want %d", c.in, got, c.want)
+		}
+	}
+	// The defaults are left out of the command; a choice against them is in.
+	ha := serverInit{noNode: true, patroni: []string{"a@db1", "b@db2"}, judge: judgeSpec{Replicas: 2}}
+	if f := strings.Join(ha.initFlags(), " "); strings.Contains(f, "--judge-replicas") {
+		t.Errorf("two judges on three machines named: %s", f)
+	}
+	one := serverInit{judge: judgeSpec{Replicas: 2}}
+	if f := strings.Join(one.initFlags(), " "); !strings.Contains(f, "--judge-replicas 2") {
+		t.Errorf("two judges on one machine not named: %s", f)
+	}
+}
diff --git a/internal/cli/serverinit_cluster.go b/internal/cli/serverinit_cluster.go
index 6d5d1818..a63b4625 100644
--- a/internal/cli/serverinit_cluster.go
+++ b/internal/cli/serverinit_cluster.go
@@ -719,13 +719,13 @@ type cpuSplit struct{ judge, starter int }
 // the starter on one 4-core control plane all ran on all four: under load
 // most judgments missed their budget and the requests were refused.
 //
-// A judge needs two cores: a judgment of about 280 tokens took 8.0 s on
-// one, 4.2 s on two and 2.3 s on four, against a 5 s budget. When this
-// machine is the node, each judge replica gets two (one each only below four
-// CPUs, where two would not fit both), and the starter what is left, up to
-// 8, or no reservation at all when nothing is, rather than a starter that
-// fits nowhere. Otherwise two a judge, on whichever node takes it, and the
-// starter, on a node not known yet, none.
+// A judge needs cores: a judgment of about 280 tokens took 8.0 s on one,
+// 4.2 s on two and 2.3 s on four, against a 5 s budget. On one machine its
+// one replica gets up to four; where there are two, two each (one each only
+// where two would not fit both). The starter has what is left, up to 8, or
+// no reservation at all when nothing is, rather than a starter that fits
+// nowhere. A machine that is not the node reserves two a judge on whichever
+// node takes it, and the starter, on a node not known yet, none.
 func (in *serverInit) cpuPlan() cpuSplit {
 	if in.noNode {
 		return cpuSplit{judge: judgeCores}
@@ -742,7 +742,10 @@ func (in *serverInit) cpuPlan() cpuSplit {
 		judges = in.judgeFor().Replicas
 	}
 	judge := judgeCores
-	if judges > 0 && judges*judge > n {
+	switch {
+	case judges == 1:
+		judge = min(n, judgeCoresAlone)
+	case judges > 0 && judges*judge > n:
 		judge = max(1, n/judges)
 	}
 	left := max(n-judges*judge, 0)
@@ -751,8 +754,10 @@ func (in *serverInit) cpuPlan() cpuSplit {
 
 // judgeCores and judgeMemoryGB are what a judge replica needs: two cores
 // for a judgment within its budget, and 2 GB for its 1.6 with no prompt
-// cache.
+// cache. judgeCoresAlone is what the one judge of a single machine takes,
+// past which a model this small hardly gets faster.
 const (
-	judgeCores    = 2
-	judgeMemoryGB = 2
+	judgeCores      = 2
+	judgeCoresAlone = 4
+	judgeMemoryGB   = 2
 )
diff --git a/internal/cli/tui_choices.go b/internal/cli/tui_choices.go
index ab3376f7..2677edd9 100644
--- a/internal/cli/tui_choices.go
+++ b/internal/cli/tui_choices.go
@@ -282,7 +282,7 @@ func newInstallForm(in *serverInit, host string, found []string, ha bool) *insta
 		"The request is served unjudged and marked so in the logs. Nothing is refused for the judge's sake.",
 	}
 	f.judgeCopies = textSetupField("Copies", strconv.Itoa(j.Replicas), "2",
-		"Each reserves 2 GB and two CPU cores on whichever node has room: on one core a judgment takes longer than its budget.")
+		"On one machine one copy, on up to four cores; with more machines two, two cores each, on different nodes. Each reserves 2 GB.")
 	f.judgeBudget = textSetupField("Waits at most", durationYAML(j.Budget), "5s",
 		"A short text is judged in about two seconds on CPUs.")
 	judgeFields := []*setupField{f.judgeFail, f.judgeCopies, f.judgeBudget, headingField("Refuses")}
diff --git a/internal/cli/tui_setup.go b/internal/cli/tui_setup.go
index 976de622..845262c4 100644
--- a/internal/cli/tui_setup.go
+++ b/internal/cli/tui_setup.go
@@ -188,6 +188,8 @@ func newSetupModel(host string, ips []string) setupModel {
 	// nodes are added once it is up. Either can still be chosen.
 	in.noNode, in.noModel = true, true
 	in.standbys = true
+	// Two judges, on two of the three machines' nodes.
+	in.judge.Replicas = 2
 	return setupModel{
 		ref: &progRef{}, host: host, ips: ips, in: &in, choices: newInstallForm(&in, host, ips, true),
 		db: [2]dbMachine{newDBMachine(1), newDBMachine(2)}, spin: newSpinner(), width: 100, height: 30,