diff --git a/app/models/_associations.py b/app/models/_associations.py
index d41cc8b..a7eb124 100644
--- a/app/models/_associations.py
+++ b/app/models/_associations.py
@@ -37,3 +37,13 @@ tryout_coaches = db.Table(
         'coach_id', db.Integer, db.ForeignKey('users.id', ondelete='CASCADE'), primary_key=True
     ),
 )
+
+tryout_managers = db.Table(
+    'tryout_managers',
+    db.Column(
+        'tryout_id', db.Integer, db.ForeignKey('tryouts.id', ondelete='CASCADE'), primary_key=True
+    ),
+    db.Column(
+        'manager_id', db.Integer, db.ForeignKey('users.id', ondelete='CASCADE'), primary_key=True
+    ),
+)
diff --git a/app/models/tryout/tryout.py b/app/models/tryout/tryout.py
index 6a6cbf2..1f680d2 100644
--- a/app/models/tryout/tryout.py
+++ b/app/models/tryout/tryout.py
@@ -1,7 +1,7 @@
 """Tryout event for player evaluations and team formation."""
 
 from app.extensions import db
-from app.models._associations import tryout_coaches
+from app.models._associations import tryout_coaches, tryout_managers
 from app.time_utils import utc_now_naive
 
 
@@ -20,16 +20,17 @@ class Tryout(db.Model):
     max_players = db.Column(db.Integer, nullable=True)
     created_by = db.Column(db.Integer, db.ForeignKey('users.id'), nullable=False)
     target_org_team_id = db.Column(db.Integer, db.ForeignKey('org_teams.id'), nullable=True)
-    manager_id = db.Column(db.Integer, db.ForeignKey('users.id'), nullable=True)
+    manager_id = db.Column(db.Integer, db.ForeignKey('users.id'), nullable=True)  # deprecated, kept for migration
     coach_id = db.Column(
         db.Integer, db.ForeignKey('users.id'), nullable=True
     )  # deprecated, kept for migration
     created_at = db.Column(db.DateTime, default=utc_now_naive)
 
     creator = db.relationship('User', foreign_keys=[created_by], backref='created_tryouts')
-    manager = db.relationship('User', foreign_keys=[manager_id], backref='managed_tryouts')
+    manager = db.relationship('User', foreign_keys=[manager_id], backref='managed_tryouts')  # deprecated
     coach = db.relationship('User', foreign_keys=[coach_id], backref='_deprecated_coached_tryouts')
     coaches = db.relationship('User', secondary=tryout_coaches, backref='coached_tryouts')
+    managers = db.relationship('User', secondary=tryout_managers, backref='managed_tryouts_m2m')
     registrations = db.relationship('TryoutRegistration', backref='tryout', lazy='dynamic')
     evaluations = db.relationship('Evaluation', backref='tryout', lazy='dynamic')
     teams = db.relationship('Team', backref='tryout', lazy='dynamic')
@@ -47,3 +48,17 @@ class Tryout(db.Model):
         if self.end_date is not None:
             return self.end_date < today
         return self.date < today
+
+    def get_managers(self):
+        """Managers attached to this tryout, both legacy and many-to-many."""
+        manager_list = list(self.managers)
+        if not manager_list and self.manager:
+            return [self.manager]
+        return manager_list
+
+    def get_coaches(self):
+        """Coaches attached to this tryout, both legacy and many-to-many."""
+        coach_list = list(self.coaches)
+        if not coach_list and self.coach:
+            return [self.coach]
+        return coach_list
diff --git a/app/models/user_model/manager.py b/app/models/user_model/manager.py
index aa95fb3..501b111 100644
--- a/app/models/user_model/manager.py
+++ b/app/models/user_model/manager.py
@@ -21,7 +21,11 @@ class Manager(User):
         return True
 
     def can_manage_this_tryout(self, tryout):
-        return tryout.created_by == self.id or tryout.manager_id == self.id
+        return (
+            tryout.created_by == self.id
+            or tryout.manager_id == self.id
+            or any(m.id == self.id for m in tryout.managers)
+        )
 
     def can_manage_this_org_team(self, org_team):
         return True
@@ -32,7 +36,13 @@ class Manager(User):
         from app.models.tryout.tryout import Tryout
 
         return (
-            Tryout.query.filter(or_(Tryout.created_by == self.id, Tryout.manager_id == self.id))
+            Tryout.query.filter(
+                or_(
+                    Tryout.created_by == self.id,
+                    Tryout.manager_id == self.id,
+                    Tryout.managers.any(id=self.id),
+                )
+            )
             .order_by(Tryout.date)
             .all()
         )
diff --git a/app/routes/tryouts.py b/app/routes/tryouts.py
index db2468c..e537463 100644
--- a/app/routes/tryouts.py
+++ b/app/routes/tryouts.py
@@ -51,7 +51,7 @@ def can_manage():
 
 def tryout_form_payload():
     """The tryout form, shaped for marshmallow (ARCH-005)."""
-    return form_payload(list_fields=('coach_ids',), optional_blank=())
+    return form_payload(list_fields=('coach_ids', 'manager_ids'), optional_blank=())
 
 
 def coaches_from_ids(coach_ids):
@@ -67,6 +67,13 @@ def coaches_from_ids(coach_ids):
     return User.query.filter(User.id.in_(coach_ids), User.role == 'coach').all()
 
 
+def managers_from_ids(manager_ids):
+    """The manager accounts behind these ids, filtered by role."""
+    if not manager_ids:
+        return []
+    return User.query.filter(User.id.in_(manager_ids), User.role == 'manager').all()
+
+
 def _users_by_id(user_ids):
     """Load these users in one query, keyed by id.
 
@@ -160,12 +167,12 @@ def create_tryout():
             created_by=current_user.id,
             status='upcoming',
             target_org_team_id=data['target_org_team_id'],
-            manager_id=data['manager_id'],
         )
         db.session.add(tryout)
         db.session.flush()
 
         tryout.coaches = coaches_from_ids(data['coach_ids'])
+        tryout.managers = managers_from_ids(data['manager_ids'])
 
         db.session.commit()
         flash(_('Tryout created successfully!'), 'success')
@@ -221,8 +228,14 @@ def edit_tryout(tryout_id):
         tryout.location = data['location']
         tryout.max_players = data['max_players']
         tryout.target_org_team_id = data['target_org_team_id']
-        tryout.manager_id = data['manager_id']
-        tryout.coaches = coaches_from_ids(data['coach_ids'])
+
+        # Only update staff lists when the form explicitly sends them.
+        # An absent checkbox group (all unchecked or JS failed) means
+        # \"don't change\", not \"remove everyone\".
+        if 'coach_ids' in request.form:
+            tryout.coaches = coaches_from_ids(data['coach_ids'])
+        if 'manager_ids' in request.form:
+            tryout.managers = managers_from_ids(data['manager_ids'])
 
         db.session.commit()
         flash(_('Tryout updated successfully!'), 'success')
@@ -241,7 +254,7 @@ def view_tryout(tryout_id):
     if isinstance(current_user, Admin):
         can_view = True
     elif isinstance(current_user, Manager):
-        can_view = tryout.created_by == current_user.id or tryout.manager_id == current_user.id
+        can_view = current_user.can_manage_this_tryout(tryout)
     elif isinstance(current_user, Coach):
         can_view = current_user.can_manage_this_tryout(tryout)
     elif isinstance(current_user, Player):
diff --git a/app/templates/pages/batch_evaluate.html b/app/templates/pages/batch_evaluate.html
index 815e763..0140f15 100644
--- a/app/templates/pages/batch_evaluate.html
+++ b/app/templates/pages/batch_evaluate.html
@@ -43,7 +43,7 @@
                     <div class="form-group col-4">
                         <label for="{{ field_name }}_{{ pid }}">{{ label }} (1-10)</label>
                         <div class="score-input">
-                            <input type="range" id="{{ field_name }}_{{ pid }}" name="{{ field_name }}_{{ pid }}" min="1" max="10" value="{{ existing_scores[field_name] or 5 }}" oninput="this.nextElementSibling.textContent = this.value">
+                            <input type="range" id="{{ field_name }}_{{ pid }}" name="{{ field_name }}_{{ pid }}" min="1" max="10" value="{{ existing_scores[field_name] or 5 }}" data-mirror>
                             <span class="range-value">{{ existing_scores[field_name] or 5 }}</span>
                         </div>
                     </div>
diff --git a/app/templates/pages/players_to_evaluate.html b/app/templates/pages/players_to_evaluate.html
index 93c8048..a6f2127 100644
--- a/app/templates/pages/players_to_evaluate.html
+++ b/app/templates/pages/players_to_evaluate.html
@@ -15,7 +15,7 @@
                 <table class="table">
                     <thead>
                         <tr>
-                            <th><input type="checkbox" id="select-all" onclick="toggleAll(this)"></th>
+                            <th><input type="checkbox" id="select-all" data-action="toggle-all"></th>
                             <th>Player</th>
                             <th>Contact</th>
                             <th>Attendance</th>
@@ -70,12 +70,20 @@
     </div>
 </div>
 
-<script>
-function toggleAll(master) {
+{% endblock %}
+
+{% block scripts %}
+<script nonce="{{ csp_nonce }}">
+function toggleAll() {
     var boxes = document.querySelectorAll('.player-check');
+    var master = document.getElementById('select-all');
     for (var i = 0; i < boxes.length; i++) {
         boxes[i].checked = master.checked;
     }
 }
+
+registerActions({
+    'toggle-all': toggleAll,
+});
 </script>
 {% endblock %}
diff --git a/app/templates/pages/teams.html b/app/templates/pages/teams.html
index a4b56b6..c1e0d93 100644
--- a/app/templates/pages/teams.html
+++ b/app/templates/pages/teams.html
@@ -300,6 +300,9 @@
     </div>
 </div>
 
+{% endblock %}
+
+{% block scripts %}
 <script nonce="{{ csp_nonce }}">
 function showCreateForm() {
     document.getElementById('createTeamForm').classList.remove('hidden');
diff --git a/app/templates/pages/tryout_form.html b/app/templates/pages/tryout_form.html
index 269ef71..614571c 100644
--- a/app/templates/pages/tryout_form.html
+++ b/app/templates/pages/tryout_form.html
@@ -67,15 +67,22 @@
                     </select>
                 </div>
                 <div class="form-group col-6">
-                    <label for="manager_id">{{ _('Assigned Manager') }}</label>
-                    <select id="manager_id" name="manager_id" class="form-select">
-                        <option value="">{{ _('-- No manager assigned --') }}</option>
+                    <label>{{ _('Assigned Managers') }}</label>
+                    <div class="checkbox-grid">
                         {% for manager in managers %}
-                        <option value="{{ manager.id }}" {% if tryout and tryout.manager_id == manager.id %}selected{% endif %}>
-{{ manager.username }}
-                        </option>
+                        {% set is_checked = false %}
+                        {% if tryout %}
+                            {% for m in tryout.get_managers() %}
+                                {% if m.id == manager.id %}{% set is_checked = true %}{% endif %}
+                            {% endfor %}
+                        {% endif %}
+                        <label class="checkbox-label">
+                            <input type="checkbox" name="manager_ids" value="{{ manager.id }}" {% if is_checked %}checked{% endif %}>
+                            <span>{{ manager.username }}</span>
+                        </label>
                         {% endfor %}
-                    </select>
+                    </div>
+                    <small class="text-muted">{{ _('Select one or more managers for this tryout.') }}</small>
                 </div>
             </div>
             <div class="form-row">
diff --git a/app/templates/pages/view_tryout.html b/app/templates/pages/view_tryout.html
index 6f0342e..4311875 100644
--- a/app/templates/pages/view_tryout.html
+++ b/app/templates/pages/view_tryout.html
@@ -70,16 +70,22 @@
                     <span class="detail-value">{{ tryout.target_org_team.name if tryout.target_org_team else 'Not specified' }}</span>
                 </div>
                 <div class="detail-item">
-                    <span class="detail-label">Manager</span>
-                    <span class="detail-value">{{ tryout.manager.username if tryout.manager else 'Not assigned' }}</span>
+                    <span class="detail-label">Manager(s)</span>
+                    <span class="detail-value">
+                        {% set mgrs = tryout.get_managers() %}
+                        {% if mgrs %}
+                            {{ mgrs | map(attribute='username') | join(', ') }}
+                        {% else %}
+                            Not assigned
+                        {% endif %}
+                    </span>
                 </div>
                 <div class="detail-item">
                     <span class="detail-label">Coaches</span>
                     <span class="detail-value">
-                        {% if tryout.coaches %}
-                            {{ tryout.coaches | map(attribute='username') | join(', ') }}
-                        {% elif tryout.coach %}
-                            {{ tryout.coach.username }}
+                        {% set cos = tryout.get_coaches() %}
+                        {% if cos %}
+                            {{ cos | map(attribute='username') | join(', ') }}
                         {% else %}
                             Not assigned
                         {% endif %}
@@ -534,6 +540,9 @@
     {% endif %}
 </div>
 
+{% endblock %}
+
+{% block scripts %}
 <style>
 .presence-toggle-btn {
     padding: 2px 7px;
diff --git a/app/validators.py b/app/validators.py
index 4271819..b14aedc 100644
--- a/app/validators.py
+++ b/app/validators.py
@@ -949,6 +949,7 @@ class TryoutSchema(StripMixin):
     target_org_team_id = fields.Integer(allow_none=True, load_default=None)
     manager_id = fields.Integer(allow_none=True, load_default=None)
     coach_ids = fields.List(fields.Integer(), load_default=list)
+    manager_ids = fields.List(fields.Integer(), load_default=list)
 
     @validates_schema
     def validate_span(self, data, **kwargs):