diff --git a/api-webapp/src/main/kotlin/org/jeudego/pairgoth/api/TournamentHandler.kt b/api-webapp/src/main/kotlin/org/jeudego/pairgoth/api/TournamentHandler.kt
index 258bf16..dd1c35d 100644
--- a/api-webapp/src/main/kotlin/org/jeudego/pairgoth/api/TournamentHandler.kt
+++ b/api-webapp/src/main/kotlin/org/jeudego/pairgoth/api/TournamentHandler.kt
@@ -2,9 +2,11 @@ package org.jeudego.pairgoth.api
 
 import com.republicate.kson.Json
 import com.republicate.kson.toJsonObject
+import com.republicate.kson.toMutableJsonObject
 import org.jeudego.pairgoth.api.ApiHandler.Companion.PAYLOAD_KEY
 import org.jeudego.pairgoth.api.ApiHandler.Companion.badRequest
 import org.jeudego.pairgoth.ext.OpenGotha
+import org.jeudego.pairgoth.model.BaseCritParams
 import org.jeudego.pairgoth.model.TeamTournament
 import org.jeudego.pairgoth.model.Tournament
 import org.jeudego.pairgoth.model.fromJson
@@ -65,7 +67,7 @@ object TournamentHandler: PairgothApiHandler {
     override fun put(request: HttpServletRequest, response: HttpServletResponse): Json? {
         // CB TODO - some checks are needed here (cannot lower rounds number if games have been played in removed rounds, for instance)
         val tournament = getTournament(request)
-        val payload = getObjectPayload(request)
+        val payload = getObjectPayload(request).toMutableJsonObject()
         // disallow changing type
         if (payload.getString("type")?.let { it != tournament.type.name } == true) badRequest("tournament type cannot be changed")
         // specific handling for 'excludeTables'
@@ -77,6 +79,46 @@ object TournamentHandler: PairgothApiHandler {
             tournament.tablesExclusion[round - 1] = tablesExclusion
             tournament.dispatchEvent(TournamentUpdated, request, tournament.toJson())
         } else {
+            // translate client-side conventions to actual parameters
+            val base = payload.getObject("pairing")?.getObject("base") as Json.MutableObject?
+            if (base != null) {
+                base.getString("randomness")?.let { randomness ->
+                    when (randomness) {
+                        "none" -> {
+                            base["random"] = 0.0
+                            base["deterministic"] = true
+                        }
+                        "deterministic" -> {
+                            base["random"] = BaseCritParams.MAX_RANDOM
+                            base["deterministic"] = true
+                        }
+                        "non-deterministic" -> {
+                            base["random"] = BaseCritParams.MAX_RANDOM
+                            base["deterministic"] = false
+                        }
+                        else -> badRequest("invalid randomness parameter: $randomness")
+                    }
+                }
+                base.getBoolean("colorBalance")?.let { colorBalance ->
+                    base["colorBalanceWeight"] =
+                        if (colorBalance) BaseCritParams.MAX_COLOR_BALANCE
+                        else 0.0
+                }
+            }
+            val main = payload.getObject("pairing")?.getObject("main") as Json.MutableObject?
+            if (main != null) {
+                main.getBoolean("firstSeedAddRating")?.let { firstSeedAddRating ->
+                    main["firstSeedAddCrit"] =
+                        if (firstSeedAddRating) "RATING"
+                        else "NONE"
+                }
+                main.getBoolean("secondSeedAddRating")?.let { secondSeedAddRating ->
+                    main["secondSeedAddCrit"] =
+                        if (secondSeedAddRating) "RATING"
+                        else "NONE"
+                }
+            }
+            // prepare updated tournament version
             val updated = Tournament.fromJson(payload, tournament)
             // copy players, games, criteria (this copy should be provided by the Tournament class - CB TODO)
             updated.players.putAll(tournament.players)
diff --git a/view-webapp/src/main/webapp/js/tour-information.inc.js b/view-webapp/src/main/webapp/js/tour-information.inc.js
index 4bdcf82..94081fc 100644
--- a/view-webapp/src/main/webapp/js/tour-information.inc.js
+++ b/view-webapp/src/main/webapp/js/tour-information.inc.js
@@ -224,17 +224,17 @@ onLoad(() => {
     let tour = {
       pairing: {
         base: {
-          deterministic: form.val('deterministic'),
-          colorBalanceWeight: form.val('colorBalance') ? 1000000.0 : 0.0 // TODO use client side boolean
+          randomness: form.val('randomness'),
+          colorBalance: form.val('colorBalance')
         },
         main: {
           mmsValueAbsent: form.val('mmsValueAbsent'),
           roundDownScore: form.val('roundDownScore'),
           sosValueAbsentUseBase: form.val('sosValueAbsentUseBase'),
           firstSeedLastRound: form.val('firstSeedLastRound'),
-          firstSeedAddCrit: form.val('firstSeedAddRating') ? 'RATING' : 'NONE', // TODO use client side boolean
+          firstSeedAddRating: form.val('firstSeedAddRating'),
           firstSeed: form.val('firstSeed'),
-          secondSeedAddCrit: form.val('secondSeedAddRating') ? 'RATING' : 'NONE', // TODO use client side boolean
+          secondSeedAddRating: form.val('secondSeedAddRating'),
           secondSeed: form.val('secondSeed'),
           upDownCompensate: form.val('upDownCompensate'),
           upDownUpperMode: form.val('upDownUpperMode'),
diff --git a/view-webapp/src/main/webapp/tour-parameters.inc.html b/view-webapp/src/main/webapp/tour-parameters.inc.html
index 15f6cae..a22e9ae 100644
--- a/view-webapp/src/main/webapp/tour-parameters.inc.html
+++ b/view-webapp/src/main/webapp/tour-parameters.inc.html
@@ -3,7 +3,14 @@
     <div class="title"><i class="dropdown icon"></i>Base parameters</div>
     <div class="content">
       <div class="field">
-        <label><input type="checkbox" name="deterministic" value="true" #if($tour.pairing.base.deterministic) checked #end>&nbsp;deterministic randomness</label>
+        <label>
+          Randomness:
+          <select name="randomness">
+            <option value="none" #if($tour.pairing.base.random == 0.0)selected#end>none</option>
+            <option value="deterministic" #if($tour.pairing.base.random != 0.0 && $tour.pairing.base.deterministic)selected#end>deterministic</option>
+            <option value="non-deterministic" #if($tour.pairing.base.random != 0.0 && !$tour.pairing.base.deterministic)selected#end>non-deterministic</option>
+          </select>
+        </label>
       </div>
       <div class="field">
         <label><input type="checkbox" name="colorBalance" value="true" #if($tour.pairing.base.colorBalanceWeight) checked #end>&nbsp;balance white and black</label>