using System;

using System.Collections.Generic;

using System.Linq;

public class Widget

{

    public OtherThing OtherThing { get; set; }

}

​

public class OtherThing

{

    public int Value { get; set; }

}

​

public class Program

{

    public static void Main()

    {

        List<Widget> widgets = new List<Widget>();

        widgets.Add(new Widget() { 

            OtherThing = null

        });

        Console.WriteLine(widgets.ToList().Count());

        Console.WriteLine(widgets.Select(w => w.OtherThing).Where(r => r != null).ToList().Count());

        Console.WriteLine(widgets.Select(w => w.OtherThing).Where(r => r != null).Count());

        Console.WriteLine(widgets.Where(r => r.OtherThing != null).Select(w => w.OtherThing).ToList().Count());

        Console.WriteLine(widgets.Where(r => r.OtherThing != null).Select(w => w.OtherThing).Count());

    }

}