diff --git a/api-webapp/src/main/kotlin/org/jeudego/pairgoth/pairing/HistoryHelper.kt b/api-webapp/src/main/kotlin/org/jeudego/pairgoth/pairing/HistoryHelper.kt
index 18c54dc..b99f9c1 100644
--- a/api-webapp/src/main/kotlin/org/jeudego/pairgoth/pairing/HistoryHelper.kt
+++ b/api-webapp/src/main/kotlin/org/jeudego/pairgoth/pairing/HistoryHelper.kt
@@ -2,7 +2,7 @@ package org.jeudego.pairgoth.pairing
 
 import org.jeudego.pairgoth.model.*
 
-open class HistoryHelper(protected val history: List<Game>, score: Map<ID, Double>) {
+open class HistoryHelper(protected val history: List<Game>, computeScore: () -> Map<ID, Double>) {
 
     fun getCriterionValue(p: Pairable, crit: PlacementCriterion): Int {
         // Returns generic criterion
@@ -26,7 +26,7 @@ open class HistoryHelper(protected val history: List<Game>, score: Map<ID, Doubl
     open fun nbW(p: Pairable) = numberWins[p.id]
 
 
-    protected val paired: Set<Pair<Int, Int>> by lazy {
+    protected val paired: Set<Pair<ID, ID>> by lazy {
         (history.map { game ->
             Pair(game.black, game.white)
         } + history.map { game ->
@@ -36,7 +36,7 @@ open class HistoryHelper(protected val history: List<Game>, score: Map<ID, Doubl
 
     // Returns the number of games played as white
     // Only count games without handicap
-    private val colorBalance: Map<Int, Int> by lazy {
+    private val colorBalance: Map<ID, Int> by lazy {
         history.flatMap { game -> if (game.handicap == 0) {
             listOf(Pair(game.white, +1), Pair(game.black, -1))
         } else {
@@ -47,8 +47,8 @@ open class HistoryHelper(protected val history: List<Game>, score: Map<ID, Doubl
         }
     }
 
-    val numberWins: Map<Int, Double> by lazy {
-        mutableMapOf<Int, Double>().apply {
+    val numberWins: Map<ID, Double> by lazy {
+        mutableMapOf<ID, Double>().apply {
             history.forEach { game ->
                 when (game.result) {
                     Game.Result.BLACK -> put(game.black, getOrDefault(game.black, 0.0) + 1.0)
@@ -63,6 +63,11 @@ open class HistoryHelper(protected val history: List<Game>, score: Map<ID, Doubl
         }
     }
 
+    // Has to be set after construction
+    private val score by lazy {
+        computeScore()
+    }
+
     // SOS related functions given a score function
     val sos by lazy {
         (history.map { game ->
@@ -114,8 +119,8 @@ open class HistoryHelper(protected val history: List<Game>, score: Map<ID, Doubl
 
 // CB TODO - a big problem with the current naive implementation is that the team score is -for now- the sum of team members individual scores
 
-class TeamOfIndividualsHistoryHelper(history: List<Game>, score: Map<ID, Double>):
-        HistoryHelper(history, score) {
+class TeamOfIndividualsHistoryHelper(history: List<Game>, computeScore: () -> Map<ID, Double>):
+        HistoryHelper(history, computeScore) {
 
     private fun Pairable.asTeam() = this as TeamTournament.Team
 
diff --git a/api-webapp/src/main/kotlin/org/jeudego/pairgoth/pairing/Solver.kt b/api-webapp/src/main/kotlin/org/jeudego/pairgoth/pairing/Solver.kt
index 5d0010d..d35fe3b 100644
--- a/api-webapp/src/main/kotlin/org/jeudego/pairgoth/pairing/Solver.kt
+++ b/api-webapp/src/main/kotlin/org/jeudego/pairgoth/pairing/Solver.kt
@@ -12,6 +12,7 @@ import kotlin.math.abs
 import kotlin.math.max
 import kotlin.math.min
 
+val DEBUG_EXPORT_WEIGHT = true
 
 private fun detRandom(max: Long, p1: Pairable, p2: Pairable): Long {
     var nR: Long = 0
@@ -353,10 +354,10 @@ sealed class Solver(
     }
 
     // Generic parameters calculation
-    private val standingScore = computeStandingScore()
-    val historyHelper =
-            if (pairables.first().let { it is TeamTournament.Team && it.teamOfIndividuals }) TeamOfIndividualsHistoryHelper(history, standingScore)
-            else HistoryHelper(history, standingScore)
+    //private val standingScore by lazy { computeStandingScore() }
+
+    val historyHelper = if (pairables.first().let { it is TeamTournament.Team && it.teamOfIndividuals }) TeamOfIndividualsHistoryHelper(history, ::computeStandingScore)
+    else HistoryHelper(history, ::computeStandingScore)
 
 
 
@@ -404,7 +405,6 @@ sealed class Solver(
     val Pairable.nbW: Double get() = historyHelper.nbW(this) ?: 0.0
 
     val Pairable.sos: Double get() = historyHelper.sos[id]!!
-
     val Pairable.sosm1: Double get() = historyHelper.sosm1[id]!!
     val Pairable.sosm2: Double get() = historyHelper.sosm2[id]!!
     val Pairable.sosos: Double get() = historyHelper.sosos[id]!!